root/drivers/pci/controller/dwc/pci-dra7xx.c
// SPDX-License-Identifier: GPL-2.0
/*
 * pcie-dra7xx - PCIe controller driver for TI DRA7xx SoCs
 *
 * Copyright (C) 2013-2014 Texas Instruments Incorporated - https://www.ti.com
 *
 * Authors: Kishon Vijay Abraham I <kishon@ti.com>
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/resource.h>
#include <linux/types.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/gpio/consumer.h>

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

/* PCIe controller wrapper DRA7XX configuration registers */

#define PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN             0x0024
#define PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MAIN         0x0028
#define ERR_SYS                                         BIT(0)
#define ERR_FATAL                                       BIT(1)
#define ERR_NONFATAL                                    BIT(2)
#define ERR_COR                                         BIT(3)
#define ERR_AXI                                         BIT(4)
#define ERR_ECRC                                        BIT(5)
#define PME_TURN_OFF                                    BIT(8)
#define PME_TO_ACK                                      BIT(9)
#define PM_PME                                          BIT(10)
#define LINK_REQ_RST                                    BIT(11)
#define LINK_UP_EVT                                     BIT(12)
#define CFG_BME_EVT                                     BIT(13)
#define CFG_MSE_EVT                                     BIT(14)
#define INTERRUPTS (ERR_SYS | ERR_FATAL | ERR_NONFATAL | ERR_COR | ERR_AXI | \
                        ERR_ECRC | PME_TURN_OFF | PME_TO_ACK | PM_PME | \
                        LINK_REQ_RST | LINK_UP_EVT | CFG_BME_EVT | CFG_MSE_EVT)

#define PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI              0x0034
#define PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI          0x0038
#define INTA                                            BIT(0)
#define INTB                                            BIT(1)
#define INTC                                            BIT(2)
#define INTD                                            BIT(3)
#define MSI                                             BIT(4)
#define LEG_EP_INTERRUPTS (INTA | INTB | INTC | INTD)

#define PCIECTRL_TI_CONF_DEVICE_TYPE                    0x0100
#define DEVICE_TYPE_EP                                  0x0
#define DEVICE_TYPE_LEG_EP                              0x1
#define DEVICE_TYPE_RC                                  0x4

#define PCIECTRL_DRA7XX_CONF_DEVICE_CMD                 0x0104
#define LTSSM_EN                                        0x1

#define PCIECTRL_DRA7XX_CONF_PHY_CS                     0x010C
#define LINK_UP                                         BIT(16)
#define DRA7XX_CPU_TO_BUS_ADDR                          0x0FFFFFFF

#define PCIECTRL_TI_CONF_INTX_ASSERT                    0x0124
#define PCIECTRL_TI_CONF_INTX_DEASSERT                  0x0128

#define PCIECTRL_TI_CONF_MSI_XMT                        0x012c
#define MSI_REQ_GRANT                                   BIT(0)
#define MSI_VECTOR_SHIFT                                7

#define PCIE_1LANE_2LANE_SELECTION                      BIT(13)
#define PCIE_B1C0_MODE_SEL                              BIT(2)
#define PCIE_B0_B1_TSYNCEN                              BIT(0)

struct dra7xx_pcie {
        struct dw_pcie          *pci;
        void __iomem            *base;          /* DT ti_conf */
        int                     phy_count;      /* DT phy-names count */
        struct phy              **phy;
        struct irq_domain       *irq_domain;
        struct clk              *clk;
        enum dw_pcie_device_mode mode;
};

struct dra7xx_pcie_of_data {
        enum dw_pcie_device_mode mode;
        u32 b1co_mode_sel_mask;
};

#define to_dra7xx_pcie(x)       dev_get_drvdata((x)->dev)

static inline u32 dra7xx_pcie_readl(struct dra7xx_pcie *pcie, u32 offset)
{
        return readl(pcie->base + offset);
}

static inline void dra7xx_pcie_writel(struct dra7xx_pcie *pcie, u32 offset,
                                      u32 value)
{
        writel(value, pcie->base + offset);
}

static u64 dra7xx_pcie_cpu_addr_fixup(struct dw_pcie *pci, u64 cpu_addr)
{
        return cpu_addr & DRA7XX_CPU_TO_BUS_ADDR;
}

static bool dra7xx_pcie_link_up(struct dw_pcie *pci)
{
        struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
        u32 reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_PHY_CS);

        return reg & LINK_UP;
}

static void dra7xx_pcie_stop_link(struct dw_pcie *pci)
{
        struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
        u32 reg;

        reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
        reg &= ~LTSSM_EN;
        dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);
}

static int dra7xx_pcie_establish_link(struct dw_pcie *pci)
{
        struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
        struct device *dev = pci->dev;
        u32 reg;

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

        reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
        reg |= LTSSM_EN;
        dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);

        return 0;
}

static void dra7xx_pcie_enable_msi_interrupts(struct dra7xx_pcie *dra7xx)
{
        dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI,
                           LEG_EP_INTERRUPTS | MSI);

        dra7xx_pcie_writel(dra7xx,
                           PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI,
                           MSI | LEG_EP_INTERRUPTS);
}

static void dra7xx_pcie_enable_wrapper_interrupts(struct dra7xx_pcie *dra7xx)
{
        dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN,
                           INTERRUPTS);
        dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MAIN,
                           INTERRUPTS);
}

static void dra7xx_pcie_enable_interrupts(struct dra7xx_pcie *dra7xx)
{
        dra7xx_pcie_enable_wrapper_interrupts(dra7xx);
        dra7xx_pcie_enable_msi_interrupts(dra7xx);
}

static int dra7xx_pcie_host_init(struct dw_pcie_rp *pp)
{
        struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
        struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);

        dra7xx_pcie_enable_interrupts(dra7xx);

        return 0;
}

static int dra7xx_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
                                irq_hw_number_t hwirq)
{
        irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
        irq_set_chip_data(irq, domain->host_data);

        return 0;
}

static const struct irq_domain_ops intx_domain_ops = {
        .map = dra7xx_pcie_intx_map,
        .xlate = pci_irqd_intx_xlate,
};

static int dra7xx_pcie_handle_msi(struct dw_pcie_rp *pp, int index)
{
        struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
        unsigned long val;
        int pos;

        val = dw_pcie_readl_dbi(pci, PCIE_MSI_INTR0_STATUS +
                                   (index * MSI_REG_CTRL_BLOCK_SIZE));
        if (!val)
                return 0;

        pos = find_first_bit(&val, MAX_MSI_IRQS_PER_CTRL);
        while (pos != MAX_MSI_IRQS_PER_CTRL) {
                generic_handle_domain_irq(pp->irq_domain,
                                          (index * MAX_MSI_IRQS_PER_CTRL) + pos);
                pos++;
                pos = find_next_bit(&val, MAX_MSI_IRQS_PER_CTRL, pos);
        }

        return 1;
}

static void dra7xx_pcie_handle_msi_irq(struct dw_pcie_rp *pp)
{
        struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
        int ret, i, count, num_ctrls;

        num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;

        /**
         * Need to make sure all MSI status bits read 0 before exiting.
         * Else, new MSI IRQs are not registered by the wrapper. Have an
         * upperbound for the loop and exit the IRQ in case of IRQ flood
         * to avoid locking up system in interrupt context.
         */
        count = 0;
        do {
                ret = 0;

                for (i = 0; i < num_ctrls; i++)
                        ret |= dra7xx_pcie_handle_msi(pp, i);
                count++;
        } while (ret && count <= 1000);

        if (count > 1000)
                dev_warn_ratelimited(pci->dev,
                                     "Too many MSI IRQs to handle\n");
}

static void dra7xx_pcie_msi_irq_handler(struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct dra7xx_pcie *dra7xx;
        struct dw_pcie_rp *pp;
        struct dw_pcie *pci;
        unsigned long reg;
        u32 bit;

        chained_irq_enter(chip, desc);

        pp = irq_desc_get_handler_data(desc);
        pci = to_dw_pcie_from_pp(pp);
        dra7xx = to_dra7xx_pcie(pci);

        reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI);
        dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI, reg);

        switch (reg) {
        case MSI:
                dra7xx_pcie_handle_msi_irq(pp);
                break;
        case INTA:
        case INTB:
        case INTC:
        case INTD:
                for_each_set_bit(bit, &reg, PCI_NUM_INTX)
                        generic_handle_domain_irq(dra7xx->irq_domain, bit);
                break;
        }

        chained_irq_exit(chip, desc);
}

static irqreturn_t dra7xx_pcie_irq_handler(int irq, void *arg)
{
        struct dra7xx_pcie *dra7xx = arg;
        struct dw_pcie *pci = dra7xx->pci;
        struct device *dev = pci->dev;
        struct dw_pcie_ep *ep = &pci->ep;
        u32 reg;

        reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN);

        if (reg & ERR_SYS)
                dev_dbg(dev, "System Error\n");

        if (reg & ERR_FATAL)
                dev_dbg(dev, "Fatal Error\n");

        if (reg & ERR_NONFATAL)
                dev_dbg(dev, "Non Fatal Error\n");

        if (reg & ERR_COR)
                dev_dbg(dev, "Correctable Error\n");

        if (reg & ERR_AXI)
                dev_dbg(dev, "AXI tag lookup fatal Error\n");

        if (reg & ERR_ECRC)
                dev_dbg(dev, "ECRC Error\n");

        if (reg & PME_TURN_OFF)
                dev_dbg(dev,
                        "Power Management Event Turn-Off message received\n");

        if (reg & PME_TO_ACK)
                dev_dbg(dev,
                        "Power Management Turn-Off Ack message received\n");

        if (reg & PM_PME)
                dev_dbg(dev, "PM Power Management Event message received\n");

        if (reg & LINK_REQ_RST)
                dev_dbg(dev, "Link Request Reset\n");

        if (reg & LINK_UP_EVT) {
                if (dra7xx->mode == DW_PCIE_EP_TYPE)
                        dw_pcie_ep_linkup(ep);
                dev_dbg(dev, "Link-up state change\n");
        }

        if (reg & CFG_BME_EVT)
                dev_dbg(dev, "CFG 'Bus Master Enable' change\n");

        if (reg & CFG_MSE_EVT)
                dev_dbg(dev, "CFG 'Memory Space Enable' change\n");

        dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN, reg);

        return IRQ_HANDLED;
}

static int dra7xx_pcie_init_irq_domain(struct dw_pcie_rp *pp)
{
        struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
        struct device *dev = pci->dev;
        struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
        struct device_node *node = dev->of_node;
        struct device_node *pcie_intc_node =  of_get_next_child(node, NULL);

        if (!pcie_intc_node) {
                dev_err(dev, "No PCIe Intc node found\n");
                return -ENODEV;
        }

        irq_set_chained_handler_and_data(pp->irq, dra7xx_pcie_msi_irq_handler,
                                         pp);
        dra7xx->irq_domain = irq_domain_create_linear(of_fwnode_handle(pcie_intc_node),
                                                      PCI_NUM_INTX, &intx_domain_ops, pp);
        of_node_put(pcie_intc_node);
        if (!dra7xx->irq_domain) {
                dev_err(dev, "Failed to get a INTx IRQ domain\n");
                return -ENODEV;
        }

        return 0;
}

static const struct dw_pcie_host_ops dra7xx_pcie_host_ops = {
        .init = dra7xx_pcie_host_init,
};

static void dra7xx_pcie_ep_init(struct dw_pcie_ep *ep)
{
        struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
        struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
        enum pci_barno bar;

        for (bar = 0; bar < PCI_STD_NUM_BARS; bar++)
                dw_pcie_ep_reset_bar(pci, bar);

        dra7xx_pcie_enable_wrapper_interrupts(dra7xx);
}

static void dra7xx_pcie_raise_intx_irq(struct dra7xx_pcie *dra7xx)
{
        dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_INTX_ASSERT, 0x1);
        mdelay(1);
        dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_INTX_DEASSERT, 0x1);
}

static void dra7xx_pcie_raise_msi_irq(struct dra7xx_pcie *dra7xx,
                                      u8 interrupt_num)
{
        u32 reg;

        reg = (interrupt_num - 1) << MSI_VECTOR_SHIFT;
        reg |= MSI_REQ_GRANT;
        dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_MSI_XMT, reg);
}

static int dra7xx_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
                                 unsigned int type, u16 interrupt_num)
{
        struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
        struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);

        switch (type) {
        case PCI_IRQ_INTX:
                dra7xx_pcie_raise_intx_irq(dra7xx);
                break;
        case PCI_IRQ_MSI:
                dra7xx_pcie_raise_msi_irq(dra7xx, interrupt_num);
                break;
        default:
                dev_err(pci->dev, "UNKNOWN IRQ type\n");
        }

        return 0;
}

static const struct pci_epc_features dra7xx_pcie_epc_features = {
        DWC_EPC_COMMON_FEATURES,
        .linkup_notifier = true,
        .msi_capable = true,
};

static const struct pci_epc_features*
dra7xx_pcie_get_features(struct dw_pcie_ep *ep)
{
        return &dra7xx_pcie_epc_features;
}

static const struct dw_pcie_ep_ops pcie_ep_ops = {
        .init = dra7xx_pcie_ep_init,
        .raise_irq = dra7xx_pcie_raise_irq,
        .get_features = dra7xx_pcie_get_features,
};

static int dra7xx_add_pcie_ep(struct dra7xx_pcie *dra7xx,
                              struct platform_device *pdev)
{
        int ret;
        struct dw_pcie_ep *ep;
        struct device *dev = &pdev->dev;
        struct dw_pcie *pci = dra7xx->pci;

        ep = &pci->ep;
        ep->ops = &pcie_ep_ops;

        pci->dbi_base = devm_platform_ioremap_resource_byname(pdev, "ep_dbics");
        if (IS_ERR(pci->dbi_base))
                return PTR_ERR(pci->dbi_base);

        pci->dbi_base2 =
                devm_platform_ioremap_resource_byname(pdev, "ep_dbics2");
        if (IS_ERR(pci->dbi_base2))
                return PTR_ERR(pci->dbi_base2);

        ret = dw_pcie_ep_init(ep);
        if (ret) {
                dev_err(dev, "failed to initialize endpoint\n");
                return ret;
        }

        ret = dw_pcie_ep_init_registers(ep);
        if (ret) {
                dev_err(dev, "Failed to initialize DWC endpoint registers\n");
                dw_pcie_ep_deinit(ep);
                return ret;
        }

        pci_epc_init_notify(ep->epc);

        return 0;
}

static int dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx,
                                struct platform_device *pdev)
{
        int ret;
        struct dw_pcie *pci = dra7xx->pci;
        struct dw_pcie_rp *pp = &pci->pp;
        struct device *dev = pci->dev;

        pp->irq = platform_get_irq(pdev, 1);
        if (pp->irq < 0)
                return pp->irq;

        /* MSI IRQ is muxed */
        pp->msi_irq[0] = -ENODEV;

        ret = dra7xx_pcie_init_irq_domain(pp);
        if (ret < 0)
                return ret;

        pci->dbi_base = devm_platform_ioremap_resource_byname(pdev, "rc_dbics");
        if (IS_ERR(pci->dbi_base))
                return PTR_ERR(pci->dbi_base);

        pp->ops = &dra7xx_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 = {
        .cpu_addr_fixup = dra7xx_pcie_cpu_addr_fixup,
        .start_link = dra7xx_pcie_establish_link,
        .stop_link = dra7xx_pcie_stop_link,
        .link_up = dra7xx_pcie_link_up,
};

static void dra7xx_pcie_disable_phy(struct dra7xx_pcie *dra7xx)
{
        int phy_count = dra7xx->phy_count;

        while (phy_count--) {
                phy_power_off(dra7xx->phy[phy_count]);
                phy_exit(dra7xx->phy[phy_count]);
        }
}

static int dra7xx_pcie_enable_phy(struct dra7xx_pcie *dra7xx)
{
        int phy_count = dra7xx->phy_count;
        int ret;
        int i;

        for (i = 0; i < phy_count; i++) {
                ret = phy_set_mode(dra7xx->phy[i], PHY_MODE_PCIE);
                if (ret < 0)
                        goto err_phy;

                ret = phy_init(dra7xx->phy[i]);
                if (ret < 0)
                        goto err_phy;

                ret = phy_power_on(dra7xx->phy[i]);
                if (ret < 0) {
                        phy_exit(dra7xx->phy[i]);
                        goto err_phy;
                }
        }

        return 0;

err_phy:
        while (--i >= 0) {
                phy_power_off(dra7xx->phy[i]);
                phy_exit(dra7xx->phy[i]);
        }

        return ret;
}

static const struct dra7xx_pcie_of_data dra7xx_pcie_rc_of_data = {
        .mode = DW_PCIE_RC_TYPE,
};

static const struct dra7xx_pcie_of_data dra7xx_pcie_ep_of_data = {
        .mode = DW_PCIE_EP_TYPE,
};

static const struct dra7xx_pcie_of_data dra746_pcie_rc_of_data = {
        .b1co_mode_sel_mask = BIT(2),
        .mode = DW_PCIE_RC_TYPE,
};

static const struct dra7xx_pcie_of_data dra726_pcie_rc_of_data = {
        .b1co_mode_sel_mask = GENMASK(3, 2),
        .mode = DW_PCIE_RC_TYPE,
};

static const struct dra7xx_pcie_of_data dra746_pcie_ep_of_data = {
        .b1co_mode_sel_mask = BIT(2),
        .mode = DW_PCIE_EP_TYPE,
};

static const struct dra7xx_pcie_of_data dra726_pcie_ep_of_data = {
        .b1co_mode_sel_mask = GENMASK(3, 2),
        .mode = DW_PCIE_EP_TYPE,
};

static const struct of_device_id of_dra7xx_pcie_match[] = {
        {
                .compatible = "ti,dra7-pcie",
                .data = &dra7xx_pcie_rc_of_data,
        },
        {
                .compatible = "ti,dra7-pcie-ep",
                .data = &dra7xx_pcie_ep_of_data,
        },
        {
                .compatible = "ti,dra746-pcie-rc",
                .data = &dra746_pcie_rc_of_data,
        },
        {
                .compatible = "ti,dra726-pcie-rc",
                .data = &dra726_pcie_rc_of_data,
        },
        {
                .compatible = "ti,dra746-pcie-ep",
                .data = &dra746_pcie_ep_of_data,
        },
        {
                .compatible = "ti,dra726-pcie-ep",
                .data = &dra726_pcie_ep_of_data,
        },
        {},
};
MODULE_DEVICE_TABLE(of, of_dra7xx_pcie_match);

/*
 * dra7xx_pcie_unaligned_memaccess: workaround for AM572x/AM571x Errata i870
 * @dra7xx: the dra7xx device where the workaround should be applied
 *
 * Access to the PCIe slave port that are not 32-bit aligned will result
 * in incorrect mapping to TLP Address and Byte enable fields. Therefore,
 * byte and half-word accesses are not possible to byte offset 0x1, 0x2, or
 * 0x3.
 *
 * To avoid this issue set PCIE_SS1_AXI2OCP_LEGACY_MODE_ENABLE to 1.
 */
static int dra7xx_pcie_unaligned_memaccess(struct device *dev)
{
        int ret;
        struct device_node *np = dev->of_node;
        unsigned int args[2];
        struct regmap *regmap;

        regmap = syscon_regmap_lookup_by_phandle_args(np, "ti,syscon-unaligned-access",
                                                      2, args);
        if (IS_ERR(regmap)) {
                dev_dbg(dev, "can't get ti,syscon-unaligned-access\n");
                return -EINVAL;
        }

        ret = regmap_update_bits(regmap, args[0], args[1], args[1]);
        if (ret)
                dev_err(dev, "failed to enable unaligned access\n");

        return ret;
}

static int dra7xx_pcie_configure_two_lane(struct device *dev,
                                          u32 b1co_mode_sel_mask)
{
        struct device_node *np = dev->of_node;
        struct regmap *pcie_syscon;
        unsigned int pcie_reg;
        u32 mask;
        u32 val;

        pcie_syscon = syscon_regmap_lookup_by_phandle_args(np, "ti,syscon-lane-sel",
                                                           1, &pcie_reg);
        if (IS_ERR(pcie_syscon)) {
                dev_err(dev, "unable to get ti,syscon-lane-sel\n");
                return -EINVAL;
        }

        mask = b1co_mode_sel_mask | PCIE_B0_B1_TSYNCEN;
        val = PCIE_B1C0_MODE_SEL | PCIE_B0_B1_TSYNCEN;
        regmap_update_bits(pcie_syscon, pcie_reg, mask, val);

        return 0;
}

static int dra7xx_pcie_probe(struct platform_device *pdev)
{
        u32 reg;
        int ret;
        int irq;
        int i;
        int phy_count;
        struct phy **phy;
        struct device_link **link;
        void __iomem *base;
        struct dw_pcie *pci;
        struct dra7xx_pcie *dra7xx;
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        char name[10];
        struct gpio_desc *reset;
        const struct dra7xx_pcie_of_data *data;
        enum dw_pcie_device_mode mode;
        u32 b1co_mode_sel_mask;

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

        mode = (enum dw_pcie_device_mode)data->mode;
        b1co_mode_sel_mask = data->b1co_mode_sel_mask;

        dra7xx = devm_kzalloc(dev, sizeof(*dra7xx), GFP_KERNEL);
        if (!dra7xx)
                return -ENOMEM;

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

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

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        base = devm_platform_ioremap_resource_byname(pdev, "ti_conf");
        if (IS_ERR(base))
                return PTR_ERR(base);

        phy_count = of_property_count_strings(np, "phy-names");
        if (phy_count < 0) {
                dev_err(dev, "unable to find the strings\n");
                return phy_count;
        }

        phy = devm_kcalloc(dev, phy_count, sizeof(*phy), GFP_KERNEL);
        if (!phy)
                return -ENOMEM;

        link = devm_kcalloc(dev, phy_count, sizeof(*link), GFP_KERNEL);
        if (!link)
                return -ENOMEM;

        dra7xx->clk = devm_clk_get_optional(dev, NULL);
        if (IS_ERR(dra7xx->clk))
                return dev_err_probe(dev, PTR_ERR(dra7xx->clk),
                                     "clock request failed");

        ret = clk_prepare_enable(dra7xx->clk);
        if (ret)
                return ret;

        for (i = 0; i < phy_count; i++) {
                snprintf(name, sizeof(name), "pcie-phy%d", i);
                phy[i] = devm_phy_get(dev, name);
                if (IS_ERR(phy[i]))
                        return PTR_ERR(phy[i]);

                link[i] = device_link_add(dev, &phy[i]->dev, DL_FLAG_STATELESS);
                if (!link[i]) {
                        ret = -EINVAL;
                        goto err_link;
                }
        }

        dra7xx->base = base;
        dra7xx->phy = phy;
        dra7xx->pci = pci;
        dra7xx->phy_count = phy_count;

        if (phy_count == 2) {
                ret = dra7xx_pcie_configure_two_lane(dev, b1co_mode_sel_mask);
                if (ret < 0)
                        dra7xx->phy_count = 1; /* Fallback to x1 lane mode */
        }

        ret = dra7xx_pcie_enable_phy(dra7xx);
        if (ret) {
                dev_err(dev, "failed to enable phy\n");
                return ret;
        }

        platform_set_drvdata(pdev, dra7xx);

        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;
        }

        reset = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);
        if (IS_ERR(reset)) {
                ret = PTR_ERR(reset);
                dev_err(&pdev->dev, "gpio request failed, ret %d\n", ret);
                goto err_gpio;
        }

        reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
        reg &= ~LTSSM_EN;
        dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);

        switch (mode) {
        case DW_PCIE_RC_TYPE:
                if (!IS_ENABLED(CONFIG_PCI_DRA7XX_HOST)) {
                        ret = -ENODEV;
                        goto err_gpio;
                }

                dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_DEVICE_TYPE,
                                   DEVICE_TYPE_RC);

                ret = dra7xx_pcie_unaligned_memaccess(dev);
                if (ret)
                        dev_err(dev, "WA for Errata i870 not applied\n");

                ret = dra7xx_add_pcie_port(dra7xx, pdev);
                if (ret < 0)
                        goto err_gpio;
                break;
        case DW_PCIE_EP_TYPE:
                if (!IS_ENABLED(CONFIG_PCI_DRA7XX_EP)) {
                        ret = -ENODEV;
                        goto err_gpio;
                }

                dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_DEVICE_TYPE,
                                   DEVICE_TYPE_EP);

                ret = dra7xx_pcie_unaligned_memaccess(dev);
                if (ret)
                        goto err_gpio;

                ret = dra7xx_add_pcie_ep(dra7xx, pdev);
                if (ret < 0)
                        goto err_gpio;
                break;
        default:
                dev_err(dev, "INVALID device type %d\n", mode);
        }
        dra7xx->mode = mode;

        ret = devm_request_threaded_irq(dev, irq, NULL, dra7xx_pcie_irq_handler,
                                        IRQF_SHARED | IRQF_ONESHOT,
                                        "dra7xx-pcie-main", dra7xx);
        if (ret) {
                dev_err(dev, "failed to request irq\n");
                goto err_deinit;
        }

        return 0;

err_deinit:
        if (dra7xx->mode == DW_PCIE_RC_TYPE)
                dw_pcie_host_deinit(&dra7xx->pci->pp);
        else
                dw_pcie_ep_deinit(&dra7xx->pci->ep);

err_gpio:
err_get_sync:
        pm_runtime_put(dev);
        pm_runtime_disable(dev);
        dra7xx_pcie_disable_phy(dra7xx);

err_link:
        while (--i >= 0)
                device_link_del(link[i]);

        return ret;
}

static int dra7xx_pcie_suspend(struct device *dev)
{
        struct dra7xx_pcie *dra7xx = dev_get_drvdata(dev);
        struct dw_pcie *pci = dra7xx->pci;
        u32 val;

        if (dra7xx->mode != DW_PCIE_RC_TYPE)
                return 0;

        /* clear MSE */
        val = dw_pcie_readl_dbi(pci, PCI_COMMAND);
        val &= ~PCI_COMMAND_MEMORY;
        dw_pcie_writel_dbi(pci, PCI_COMMAND, val);

        return 0;
}

static int dra7xx_pcie_resume(struct device *dev)
{
        struct dra7xx_pcie *dra7xx = dev_get_drvdata(dev);
        struct dw_pcie *pci = dra7xx->pci;
        u32 val;

        if (dra7xx->mode != DW_PCIE_RC_TYPE)
                return 0;

        /* set MSE */
        val = dw_pcie_readl_dbi(pci, PCI_COMMAND);
        val |= PCI_COMMAND_MEMORY;
        dw_pcie_writel_dbi(pci, PCI_COMMAND, val);

        return 0;
}

static int dra7xx_pcie_suspend_noirq(struct device *dev)
{
        struct dra7xx_pcie *dra7xx = dev_get_drvdata(dev);

        dra7xx_pcie_disable_phy(dra7xx);

        return 0;
}

static int dra7xx_pcie_resume_noirq(struct device *dev)
{
        struct dra7xx_pcie *dra7xx = dev_get_drvdata(dev);
        int ret;

        ret = dra7xx_pcie_enable_phy(dra7xx);
        if (ret) {
                dev_err(dev, "failed to enable phy\n");
                return ret;
        }

        return 0;
}

static void dra7xx_pcie_shutdown(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct dra7xx_pcie *dra7xx = dev_get_drvdata(dev);
        int ret;

        dra7xx_pcie_stop_link(dra7xx->pci);

        ret = pm_runtime_put_sync(dev);
        if (ret < 0)
                dev_dbg(dev, "pm_runtime_put_sync failed\n");

        pm_runtime_disable(dev);
        dra7xx_pcie_disable_phy(dra7xx);

        clk_disable_unprepare(dra7xx->clk);
}

static const struct dev_pm_ops dra7xx_pcie_pm_ops = {
        SYSTEM_SLEEP_PM_OPS(dra7xx_pcie_suspend, dra7xx_pcie_resume)
        NOIRQ_SYSTEM_SLEEP_PM_OPS(dra7xx_pcie_suspend_noirq,
                                  dra7xx_pcie_resume_noirq)
};

static struct platform_driver dra7xx_pcie_driver = {
        .probe = dra7xx_pcie_probe,
        .driver = {
                .name   = "dra7-pcie",
                .of_match_table = of_dra7xx_pcie_match,
                .suppress_bind_attrs = true,
                .pm     = &dra7xx_pcie_pm_ops,
        },
        .shutdown = dra7xx_pcie_shutdown,
};
module_platform_driver(dra7xx_pcie_driver);

MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
MODULE_DESCRIPTION("PCIe controller driver for TI DRA7xx SoCs");
MODULE_LICENSE("GPL v2");