// SPDX-License-Identifier: GPL-2.0
/*
 * PCIe host controller driver for Rockchip SoCs.
 *
 * Copyright (C) 2021 Rockchip Electronics Co., Ltd.
 *              http://www.rock-chips.com
 *
 * Author: Simon Xue <xxm@rock-chips.com>
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/gpio/consumer.h>
#include <linux/hw_bitfield.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>

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

/*
 * The upper 16 bits of PCIE_CLIENT_CONFIG are a write
 * mask for the lower 16 bits.
 */

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

/* General Control Register */
#define PCIE_CLIENT_GENERAL_CON         0x0
#define  PCIE_CLIENT_MODE_MASK          GENMASK(7, 4)
#define  PCIE_CLIENT_MODE_EP            0x0UL
#define  PCIE_CLIENT_MODE_RC            0x4UL
#define  PCIE_CLIENT_SET_MODE(x)        FIELD_PREP_WM16(PCIE_CLIENT_MODE_MASK, (x))
#define  PCIE_CLIENT_LD_RQ_RST_GRT      FIELD_PREP_WM16(BIT(3), 1)
#define  PCIE_CLIENT_ENABLE_LTSSM       FIELD_PREP_WM16(BIT(2), 1)
#define  PCIE_CLIENT_DISABLE_LTSSM      FIELD_PREP_WM16(BIT(2), 0)

/* Interrupt Status Register Related to Legacy Interrupt */
#define PCIE_CLIENT_INTR_STATUS_LEGACY  0x8

/* Interrupt Status Register Related to Miscellaneous Operation */
#define PCIE_CLIENT_INTR_STATUS_MISC    0x10
#define  PCIE_RDLH_LINK_UP_CHGED        BIT(1)
#define  PCIE_LINK_REQ_RST_NOT_INT      BIT(2)

/* Interrupt Mask Register Related to Legacy Interrupt */
#define PCIE_CLIENT_INTR_MASK_LEGACY    0x1c
#define  PCIE_INTR_MASK                 GENMASK(7, 0)
#define  PCIE_INTR_CLAMP(_x)            ((BIT((_x)) & PCIE_INTR_MASK))
#define  PCIE_INTR_LEGACY_MASK(x)       (PCIE_INTR_CLAMP((x)) | \
                                         (PCIE_INTR_CLAMP((x)) << 16))
#define  PCIE_INTR_LEGACY_UNMASK(x)     (PCIE_INTR_CLAMP((x)) << 16)

/* Interrupt Mask Register Related to Miscellaneous Operation */
#define PCIE_CLIENT_INTR_MASK_MISC      0x24

/* Power Management Control Register */
#define PCIE_CLIENT_POWER_CON           0x2c
#define  PCIE_CLKREQ_READY              FIELD_PREP_WM16(BIT(0), 1)
#define  PCIE_CLKREQ_NOT_READY          FIELD_PREP_WM16(BIT(0), 0)
#define  PCIE_CLKREQ_PULL_DOWN          FIELD_PREP_WM16(GENMASK(13, 12), 1)

/* RASDES TBA information */
#define PCIE_CLIENT_CDM_RASDES_TBA_INFO_CMN     0x154
#define  PCIE_CLIENT_CDM_RASDES_TBA_L1_1        BIT(4)
#define  PCIE_CLIENT_CDM_RASDES_TBA_L1_2        BIT(5)

/* Hot Reset Control Register */
#define PCIE_CLIENT_HOT_RESET_CTRL      0x180
#define  PCIE_LTSSM_APP_DLY2_EN         BIT(1)
#define  PCIE_LTSSM_APP_DLY2_DONE       BIT(3)
#define  PCIE_LTSSM_ENABLE_ENHANCE      BIT(4)

/* LTSSM Status Register */
#define PCIE_CLIENT_LTSSM_STATUS        0x300
#define  PCIE_LINKUP                    0x3
#define  PCIE_LINKUP_MASK               GENMASK(17, 16)
#define  PCIE_LTSSM_STATUS_MASK         GENMASK(5, 0)

#define PCIE_TYPE0_HDR_DBI2_OFFSET      0x100000

struct rockchip_pcie {
        struct dw_pcie pci;
        void __iomem *apb_base;
        struct phy *phy;
        struct clk_bulk_data *clks;
        unsigned int clk_cnt;
        struct reset_control *rst;
        struct gpio_desc *rst_gpio;
        struct irq_domain *irq_domain;
        const struct rockchip_pcie_of_data *data;
        bool supports_clkreq;
};

struct rockchip_pcie_of_data {
        enum dw_pcie_device_mode mode;
        const struct pci_epc_features *epc_features;
};

static int rockchip_pcie_readl_apb(struct rockchip_pcie *rockchip, u32 reg)
{
        return readl_relaxed(rockchip->apb_base + reg);
}

static void rockchip_pcie_writel_apb(struct rockchip_pcie *rockchip, u32 val,
                                     u32 reg)
{
        writel_relaxed(val, rockchip->apb_base + reg);
}

static void rockchip_pcie_intx_handler(struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct rockchip_pcie *rockchip = irq_desc_get_handler_data(desc);
        unsigned long reg, hwirq;

        chained_irq_enter(chip, desc);

        reg = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_INTR_STATUS_LEGACY);

        for_each_set_bit(hwirq, &reg, 4)
                generic_handle_domain_irq(rockchip->irq_domain, hwirq);

        chained_irq_exit(chip, desc);
}

static void rockchip_intx_mask(struct irq_data *data)
{
        rockchip_pcie_writel_apb(irq_data_get_irq_chip_data(data),
                                 PCIE_INTR_LEGACY_MASK(data->hwirq),
                                 PCIE_CLIENT_INTR_MASK_LEGACY);
};

static void rockchip_intx_unmask(struct irq_data *data)
{
        rockchip_pcie_writel_apb(irq_data_get_irq_chip_data(data),
                                 PCIE_INTR_LEGACY_UNMASK(data->hwirq),
                                 PCIE_CLIENT_INTR_MASK_LEGACY);
};

static struct irq_chip rockchip_intx_irq_chip = {
        .name                   = "INTx",
        .irq_mask               = rockchip_intx_mask,
        .irq_unmask             = rockchip_intx_unmask,
        .flags                  = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND,
};

static int rockchip_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
                                  irq_hw_number_t hwirq)
{
        irq_set_chip_and_handler(irq, &rockchip_intx_irq_chip, handle_level_irq);
        irq_set_chip_data(irq, domain->host_data);

        return 0;
}

static const struct irq_domain_ops intx_domain_ops = {
        .map = rockchip_pcie_intx_map,
};

static int rockchip_pcie_init_irq_domain(struct rockchip_pcie *rockchip)
{
        struct device *dev = rockchip->pci.dev;
        struct device_node *intc;

        intc = of_get_child_by_name(dev->of_node, "legacy-interrupt-controller");
        if (!intc) {
                dev_err(dev, "missing child interrupt-controller node\n");
                return -EINVAL;
        }

        rockchip->irq_domain = irq_domain_create_linear(of_fwnode_handle(intc), PCI_NUM_INTX,
                                                        &intx_domain_ops, rockchip);
        of_node_put(intc);
        if (!rockchip->irq_domain) {
                dev_err(dev, "failed to get a INTx IRQ domain\n");
                return -EINVAL;
        }

        return 0;
}

static u32 rockchip_pcie_get_ltssm_reg(struct rockchip_pcie *rockchip)
{
        return rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_LTSSM_STATUS);
}

static enum dw_pcie_ltssm rockchip_pcie_get_ltssm(struct dw_pcie *pci)
{
        struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
        u32 val = rockchip_pcie_readl_apb(rockchip,
                        PCIE_CLIENT_CDM_RASDES_TBA_INFO_CMN);

        if (val & PCIE_CLIENT_CDM_RASDES_TBA_L1_1)
                return DW_PCIE_LTSSM_L1_1;

        if (val & PCIE_CLIENT_CDM_RASDES_TBA_L1_2)
                return DW_PCIE_LTSSM_L1_2;

        return rockchip_pcie_get_ltssm_reg(rockchip) & PCIE_LTSSM_STATUS_MASK;
}

static void rockchip_pcie_enable_ltssm(struct rockchip_pcie *rockchip)
{
        rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_ENABLE_LTSSM,
                                 PCIE_CLIENT_GENERAL_CON);
}

static void rockchip_pcie_disable_ltssm(struct rockchip_pcie *rockchip)
{
        rockchip_pcie_writel_apb(rockchip, PCIE_CLIENT_DISABLE_LTSSM,
                                 PCIE_CLIENT_GENERAL_CON);
}

static bool rockchip_pcie_link_up(struct dw_pcie *pci)
{
        struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
        u32 val = rockchip_pcie_get_ltssm_reg(rockchip);

        return FIELD_GET(PCIE_LINKUP_MASK, val) == PCIE_LINKUP;
}

/*
 * See e.g. section '11.6.6.4 L1 Substate' in the RK3588 TRM V1.0 for the steps
 * needed to support L1 substates. Currently, just enable L1 substates for RC
 * mode if CLKREQ# is properly connected and supports-clkreq is present in DT.
 * For EP mode, there are more things should be done to actually save power in
 * L1 substates, so disable L1 substates until there is proper support.
 */
static void rockchip_pcie_configure_l1ss(struct dw_pcie *pci)
{
        struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);

        /* Enable L1 substates if CLKREQ# is properly connected */
        if (rockchip->supports_clkreq) {
                rockchip_pcie_writel_apb(rockchip, PCIE_CLKREQ_READY,
                                         PCIE_CLIENT_POWER_CON);
                pci->l1ss_support = true;
                return;
        }

        /*
         * Otherwise, assert CLKREQ# unconditionally.  Since
         * pci->l1ss_support is not set, the DWC core will prevent L1
         * Substates support from being advertised.
         */
        rockchip_pcie_writel_apb(rockchip,
                                 PCIE_CLKREQ_PULL_DOWN | PCIE_CLKREQ_NOT_READY,
                                 PCIE_CLIENT_POWER_CON);
}

static void rockchip_pcie_enable_l0s(struct dw_pcie *pci)
{
        u32 cap, lnkcap;

        /* Enable L0S capability for all SoCs */
        cap = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
        if (cap) {
                lnkcap = dw_pcie_readl_dbi(pci, cap + PCI_EXP_LNKCAP);
                lnkcap |= PCI_EXP_LNKCAP_ASPM_L0S;
                dw_pcie_dbi_ro_wr_en(pci);
                dw_pcie_writel_dbi(pci, cap + PCI_EXP_LNKCAP, lnkcap);
                dw_pcie_dbi_ro_wr_dis(pci);
        }
}

static int rockchip_pcie_start_link(struct dw_pcie *pci)
{
        struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);

        /* Reset device */
        gpiod_set_value_cansleep(rockchip->rst_gpio, 0);

        rockchip_pcie_enable_ltssm(rockchip);

        /*
         * PCIe requires the refclk to be stable for 100µs prior to releasing
         * PERST. See table 2-4 in section 2.6.2 AC Specifications of the PCI
         * Express Card Electromechanical Specification, 1.1. However, we don't
         * know if the refclk is coming from RC's PHY or external OSC. If it's
         * from RC, so enabling LTSSM is the just right place to release #PERST.
         * We need more extra time as before, rather than setting just
         * 100us as we don't know how long should the device need to reset.
         */
        msleep(PCIE_T_PVPERL_MS);
        gpiod_set_value_cansleep(rockchip->rst_gpio, 1);

        return 0;
}

static void rockchip_pcie_stop_link(struct dw_pcie *pci)
{
        struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);

        rockchip_pcie_disable_ltssm(rockchip);
}

static int rockchip_pcie_host_init(struct dw_pcie_rp *pp)
{
        struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
        struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);
        struct device *dev = rockchip->pci.dev;
        int irq, ret;

        irq = of_irq_get_byname(dev->of_node, "legacy");
        if (irq < 0)
                return irq;

        pci->dbi_base2 = pci->dbi_base + PCIE_TYPE0_HDR_DBI2_OFFSET;

        ret = rockchip_pcie_init_irq_domain(rockchip);
        if (ret < 0)
                dev_err(dev, "failed to init irq domain\n");

        irq_set_chained_handler_and_data(irq, rockchip_pcie_intx_handler,
                                         rockchip);

        rockchip_pcie_configure_l1ss(pci);
        rockchip_pcie_enable_l0s(pci);

        /* Disable Root Ports BAR0 and BAR1 as they report bogus size */
        dw_pcie_writel_dbi2(pci, PCI_BASE_ADDRESS_0, 0x0);
        dw_pcie_writel_dbi2(pci, PCI_BASE_ADDRESS_1, 0x0);

        return 0;
}

static const struct dw_pcie_host_ops rockchip_pcie_host_ops = {
        .init = rockchip_pcie_host_init,
};

/*
 * ATS does not work on RK3588 when running in EP mode.
 *
 * After the host has enabled ATS on the EP side, it will send an IOTLB
 * invalidation request to the EP side. However, the RK3588 will never send
 * a completion back and eventually the host will print an IOTLB_INV_TIMEOUT
 * error, and the EP will not be operational. If we hide the ATS capability,
 * things work as expected.
 */
static void rockchip_pcie_ep_hide_broken_ats_cap_rk3588(struct dw_pcie_ep *ep)
{
        struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
        struct device *dev = pci->dev;

        /* Only hide the ATS capability for RK3588 running in EP mode. */
        if (!of_device_is_compatible(dev->of_node, "rockchip,rk3588-pcie-ep"))
                return;

        dw_pcie_remove_ext_capability(pci, PCI_EXT_CAP_ID_ATS);
}

static void rockchip_pcie_ep_init(struct dw_pcie_ep *ep)
{
        struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
        enum pci_barno bar;

        rockchip_pcie_enable_l0s(pci);
        rockchip_pcie_ep_hide_broken_ats_cap_rk3588(ep);

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

static int rockchip_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);

        switch (type) {
        case PCI_IRQ_INTX:
                return dw_pcie_ep_raise_intx_irq(ep, func_no);
        case PCI_IRQ_MSI:
                return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
        case PCI_IRQ_MSIX:
                return dw_pcie_ep_raise_msix_irq(ep, func_no, interrupt_num);
        default:
                dev_err(pci->dev, "UNKNOWN IRQ type\n");
        }

        return 0;
}

static const struct pci_epc_features rockchip_pcie_epc_features_rk3568 = {
        DWC_EPC_COMMON_FEATURES,
        .linkup_notifier = true,
        .msi_capable = true,
        .msix_capable = true,
        .align = SZ_64K,
        .bar[BAR_0] = { .type = BAR_RESIZABLE, },
        .bar[BAR_1] = { .type = BAR_RESIZABLE, },
        .bar[BAR_2] = { .type = BAR_RESIZABLE, },
        .bar[BAR_3] = { .type = BAR_RESIZABLE, },
        .bar[BAR_4] = { .type = BAR_RESIZABLE, },
        .bar[BAR_5] = { .type = BAR_RESIZABLE, },
};

/*
 * BAR4 on rk3588 exposes the ATU Port Logic Structure to the host regardless of
 * iATU settings for BAR4. This means that BAR4 cannot be used by an EPF driver,
 * so mark it as RESERVED. (rockchip_pcie_ep_init() will disable all BARs by
 * default.) If the host could write to BAR4, the iATU settings (for all other
 * BARs) would be overwritten, resulting in (all other BARs) no longer working.
 */
static const struct pci_epc_features rockchip_pcie_epc_features_rk3588 = {
        DWC_EPC_COMMON_FEATURES,
        .linkup_notifier = true,
        .msi_capable = true,
        .msix_capable = true,
        .align = SZ_64K,
        .bar[BAR_0] = { .type = BAR_RESIZABLE, },
        .bar[BAR_1] = { .type = BAR_RESIZABLE, },
        .bar[BAR_2] = { .type = BAR_RESIZABLE, },
        .bar[BAR_3] = { .type = BAR_RESIZABLE, },
        .bar[BAR_4] = { .type = BAR_RESERVED, },
        .bar[BAR_5] = { .type = BAR_RESIZABLE, },
};

static const struct pci_epc_features *
rockchip_pcie_get_features(struct dw_pcie_ep *ep)
{
        struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
        struct rockchip_pcie *rockchip = to_rockchip_pcie(pci);

        return rockchip->data->epc_features;
}

static const struct dw_pcie_ep_ops rockchip_pcie_ep_ops = {
        .init = rockchip_pcie_ep_init,
        .raise_irq = rockchip_pcie_raise_irq,
        .get_features = rockchip_pcie_get_features,
};

static int rockchip_pcie_clk_init(struct rockchip_pcie *rockchip)
{
        struct device *dev = rockchip->pci.dev;
        int ret;

        ret = devm_clk_bulk_get_all(dev, &rockchip->clks);
        if (ret < 0)
                return dev_err_probe(dev, ret, "failed to get clocks\n");

        rockchip->clk_cnt = ret;

        ret = clk_bulk_prepare_enable(rockchip->clk_cnt, rockchip->clks);
        if (ret)
                return dev_err_probe(dev, ret, "failed to enable clocks\n");

        return 0;
}

static int rockchip_pcie_resource_get(struct platform_device *pdev,
                                      struct rockchip_pcie *rockchip)
{
        rockchip->apb_base = devm_platform_ioremap_resource_byname(pdev, "apb");
        if (IS_ERR(rockchip->apb_base))
                return dev_err_probe(&pdev->dev, PTR_ERR(rockchip->apb_base),
                                     "failed to map apb registers\n");

        rockchip->rst_gpio = devm_gpiod_get_optional(&pdev->dev, "reset",
                                                     GPIOD_OUT_LOW);
        if (IS_ERR(rockchip->rst_gpio))
                return dev_err_probe(&pdev->dev, PTR_ERR(rockchip->rst_gpio),
                                     "failed to get reset gpio\n");

        rockchip->rst = devm_reset_control_array_get_exclusive(&pdev->dev);
        if (IS_ERR(rockchip->rst))
                return dev_err_probe(&pdev->dev, PTR_ERR(rockchip->rst),
                                     "failed to get reset lines\n");

        rockchip->supports_clkreq = of_property_read_bool(pdev->dev.of_node,
                                                          "supports-clkreq");

        return 0;
}

static int rockchip_pcie_phy_init(struct rockchip_pcie *rockchip)
{
        struct device *dev = rockchip->pci.dev;
        int ret;

        rockchip->phy = devm_phy_get(dev, "pcie-phy");
        if (IS_ERR(rockchip->phy))
                return dev_err_probe(dev, PTR_ERR(rockchip->phy),
                                     "missing PHY\n");

        ret = phy_init(rockchip->phy);
        if (ret < 0)
                return ret;

        ret = phy_power_on(rockchip->phy);
        if (ret)
                phy_exit(rockchip->phy);

        return ret;
}

static void rockchip_pcie_phy_deinit(struct rockchip_pcie *rockchip)
{
        phy_power_off(rockchip->phy);
        phy_exit(rockchip->phy);
}

static const struct dw_pcie_ops dw_pcie_ops = {
        .link_up = rockchip_pcie_link_up,
        .start_link = rockchip_pcie_start_link,
        .stop_link = rockchip_pcie_stop_link,
        .get_ltssm = rockchip_pcie_get_ltssm,
};

static irqreturn_t rockchip_pcie_ep_sys_irq_thread(int irq, void *arg)
{
        struct rockchip_pcie *rockchip = arg;
        struct dw_pcie *pci = &rockchip->pci;
        struct device *dev = pci->dev;
        u32 reg, val;

        reg = rockchip_pcie_readl_apb(rockchip, PCIE_CLIENT_INTR_STATUS_MISC);
        rockchip_pcie_writel_apb(rockchip, reg, PCIE_CLIENT_INTR_STATUS_MISC);

        dev_dbg(dev, "PCIE_CLIENT_INTR_STATUS_MISC: %#x\n", reg);
        dev_dbg(dev, "LTSSM_STATUS: %#x\n", rockchip_pcie_get_ltssm_reg(rockchip));

        if (reg & PCIE_LINK_REQ_RST_NOT_INT) {
                dev_dbg(dev, "hot reset or link-down reset\n");
                dw_pcie_ep_linkdown(&pci->ep);
                /* Stop delaying link training. */
                val = FIELD_PREP_WM16(PCIE_LTSSM_APP_DLY2_DONE, 1);
                rockchip_pcie_writel_apb(rockchip, val,
                                         PCIE_CLIENT_HOT_RESET_CTRL);
        }

        if (reg & PCIE_RDLH_LINK_UP_CHGED) {
                if (rockchip_pcie_link_up(pci)) {
                        dev_dbg(dev, "link up\n");
                        dw_pcie_ep_linkup(&pci->ep);
                }
        }

        return IRQ_HANDLED;
}

static int rockchip_pcie_configure_rc(struct rockchip_pcie *rockchip)
{
        struct dw_pcie_rp *pp;
        u32 val;

        if (!IS_ENABLED(CONFIG_PCIE_ROCKCHIP_DW_HOST))
                return -ENODEV;

        /* LTSSM enable control mode */
        val = FIELD_PREP_WM16(PCIE_LTSSM_ENABLE_ENHANCE, 1);
        rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);

        rockchip_pcie_writel_apb(rockchip,
                                 PCIE_CLIENT_SET_MODE(PCIE_CLIENT_MODE_RC),
                                 PCIE_CLIENT_GENERAL_CON);

        pp = &rockchip->pci.pp;
        pp->ops = &rockchip_pcie_host_ops;

        return dw_pcie_host_init(pp);
}

static int rockchip_pcie_configure_ep(struct platform_device *pdev,
                                      struct rockchip_pcie *rockchip)
{
        struct device *dev = &pdev->dev;
        int irq, ret;
        u32 val;

        if (!IS_ENABLED(CONFIG_PCIE_ROCKCHIP_DW_EP))
                return -ENODEV;

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

        ret = devm_request_threaded_irq(dev, irq, NULL,
                                        rockchip_pcie_ep_sys_irq_thread,
                                        IRQF_ONESHOT, "pcie-sys-ep", rockchip);
        if (ret) {
                dev_err(dev, "failed to request PCIe sys IRQ\n");
                return ret;
        }

        /*
         * LTSSM enable control mode, and automatically delay link training on
         * hot reset/link-down reset.
         */
        val = FIELD_PREP_WM16(PCIE_LTSSM_ENABLE_ENHANCE, 1) |
              FIELD_PREP_WM16(PCIE_LTSSM_APP_DLY2_EN, 1);
        rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_HOT_RESET_CTRL);

        rockchip_pcie_writel_apb(rockchip,
                                 PCIE_CLIENT_SET_MODE(PCIE_CLIENT_MODE_EP),
                                 PCIE_CLIENT_GENERAL_CON);

        rockchip->pci.ep.ops = &rockchip_pcie_ep_ops;
        rockchip->pci.ep.page_size = SZ_64K;

        dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));

        ret = dw_pcie_ep_init(&rockchip->pci.ep);
        if (ret) {
                dev_err(dev, "failed to initialize endpoint\n");
                return ret;
        }

        ret = dw_pcie_ep_init_registers(&rockchip->pci.ep);
        if (ret) {
                dev_err(dev, "failed to initialize DWC endpoint registers\n");
                dw_pcie_ep_deinit(&rockchip->pci.ep);
                return ret;
        }

        pci_epc_init_notify(rockchip->pci.ep.epc);

        /* unmask DLL up/down indicator and hot reset/link-down reset */
        val = FIELD_PREP_WM16(PCIE_RDLH_LINK_UP_CHGED, 0) |
              FIELD_PREP_WM16(PCIE_LINK_REQ_RST_NOT_INT, 0);
        rockchip_pcie_writel_apb(rockchip, val, PCIE_CLIENT_INTR_MASK_MISC);

        return ret;
}

static int rockchip_pcie_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct rockchip_pcie *rockchip;
        const struct rockchip_pcie_of_data *data;
        int ret;

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

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

        platform_set_drvdata(pdev, rockchip);

        rockchip->pci.dev = dev;
        rockchip->pci.ops = &dw_pcie_ops;
        rockchip->data = data;

        /* Default N_FTS value (210) is broken, override it to 255 */
        rockchip->pci.n_fts[0] = 255; /* Gen1 */
        rockchip->pci.n_fts[1] = 255; /* Gen2+ */

        ret = rockchip_pcie_resource_get(pdev, rockchip);
        if (ret)
                return ret;

        ret = reset_control_assert(rockchip->rst);
        if (ret)
                return ret;

        /* DON'T MOVE ME: must be enable before PHY init */
        ret = devm_regulator_get_enable_optional(dev, "vpcie3v3");
        if (ret < 0 && ret != -ENODEV)
                return dev_err_probe(dev, ret,
                                     "failed to enable vpcie3v3 regulator\n");

        ret = rockchip_pcie_phy_init(rockchip);
        if (ret)
                return dev_err_probe(dev, ret,
                                     "failed to initialize the phy\n");

        ret = reset_control_deassert(rockchip->rst);
        if (ret)
                goto deinit_phy;

        ret = rockchip_pcie_clk_init(rockchip);
        if (ret)
                goto deinit_phy;

        switch (data->mode) {
        case DW_PCIE_RC_TYPE:
                ret = rockchip_pcie_configure_rc(rockchip);
                if (ret)
                        goto deinit_clk;
                break;
        case DW_PCIE_EP_TYPE:
                ret = rockchip_pcie_configure_ep(pdev, rockchip);
                if (ret)
                        goto deinit_clk;
                break;
        default:
                dev_err(dev, "INVALID device type %d\n", data->mode);
                ret = -EINVAL;
                goto deinit_clk;
        }

        return 0;

deinit_clk:
        clk_bulk_disable_unprepare(rockchip->clk_cnt, rockchip->clks);
deinit_phy:
        rockchip_pcie_phy_deinit(rockchip);

        return ret;
}

static const struct rockchip_pcie_of_data rockchip_pcie_rc_of_data_rk3568 = {
        .mode = DW_PCIE_RC_TYPE,
};

static const struct rockchip_pcie_of_data rockchip_pcie_ep_of_data_rk3568 = {
        .mode = DW_PCIE_EP_TYPE,
        .epc_features = &rockchip_pcie_epc_features_rk3568,
};

static const struct rockchip_pcie_of_data rockchip_pcie_ep_of_data_rk3588 = {
        .mode = DW_PCIE_EP_TYPE,
        .epc_features = &rockchip_pcie_epc_features_rk3588,
};

static const struct of_device_id rockchip_pcie_of_match[] = {
        {
                .compatible = "rockchip,rk3568-pcie",
                .data = &rockchip_pcie_rc_of_data_rk3568,
        },
        {
                .compatible = "rockchip,rk3568-pcie-ep",
                .data = &rockchip_pcie_ep_of_data_rk3568,
        },
        {
                .compatible = "rockchip,rk3588-pcie-ep",
                .data = &rockchip_pcie_ep_of_data_rk3588,
        },
        {},
};

static struct platform_driver rockchip_pcie_driver = {
        .driver = {
                .name   = "rockchip-dw-pcie",
                .of_match_table = rockchip_pcie_of_match,
                .suppress_bind_attrs = true,
        },
        .probe = rockchip_pcie_probe,
};
builtin_platform_driver(rockchip_pcie_driver);