/*
 * Copyright (C) 2014 Hauke Mehrtens <hauke@hauke-m.de>
 * Copyright (C) 2015 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/mbus.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/phy/phy.h>

#include "pcie-iproc.h"

#define EP_PERST_SOURCE_SELECT_SHIFT 2
#define EP_PERST_SOURCE_SELECT       BIT(EP_PERST_SOURCE_SELECT_SHIFT)
#define EP_MODE_SURVIVE_PERST_SHIFT  1
#define EP_MODE_SURVIVE_PERST        BIT(EP_MODE_SURVIVE_PERST_SHIFT)
#define RC_PCIE_RST_OUTPUT_SHIFT     0
#define RC_PCIE_RST_OUTPUT           BIT(RC_PCIE_RST_OUTPUT_SHIFT)
#define PAXC_RESET_MASK              0x7f

#define GIC_V3_CFG_SHIFT             0
#define GIC_V3_CFG                   BIT(GIC_V3_CFG_SHIFT)

#define MSI_ENABLE_CFG_SHIFT         0
#define MSI_ENABLE_CFG               BIT(MSI_ENABLE_CFG_SHIFT)

#define CFG_IND_ADDR_MASK            0x00001ffc

#define CFG_ADDR_BUS_NUM_SHIFT       20
#define CFG_ADDR_BUS_NUM_MASK        0x0ff00000
#define CFG_ADDR_DEV_NUM_SHIFT       15
#define CFG_ADDR_DEV_NUM_MASK        0x000f8000
#define CFG_ADDR_FUNC_NUM_SHIFT      12
#define CFG_ADDR_FUNC_NUM_MASK       0x00007000
#define CFG_ADDR_REG_NUM_SHIFT       2
#define CFG_ADDR_REG_NUM_MASK        0x00000ffc
#define CFG_ADDR_CFG_TYPE_SHIFT      0
#define CFG_ADDR_CFG_TYPE_MASK       0x00000003

#define SYS_RC_INTX_MASK             0xf

#define PCIE_PHYLINKUP_SHIFT         3
#define PCIE_PHYLINKUP               BIT(PCIE_PHYLINKUP_SHIFT)
#define PCIE_DL_ACTIVE_SHIFT         2
#define PCIE_DL_ACTIVE               BIT(PCIE_DL_ACTIVE_SHIFT)

#define APB_ERR_EN_SHIFT             0
#define APB_ERR_EN                   BIT(APB_ERR_EN_SHIFT)

/* derive the enum index of the outbound/inbound mapping registers */
#define MAP_REG(base_reg, index)      ((base_reg) + (index) * 2)

/*
 * Maximum number of outbound mapping window sizes that can be supported by any
 * OARR/OMAP mapping pair
 */
#define MAX_NUM_OB_WINDOW_SIZES      4

#define OARR_VALID_SHIFT             0
#define OARR_VALID                   BIT(OARR_VALID_SHIFT)
#define OARR_SIZE_CFG_SHIFT          1

/*
 * Maximum number of inbound mapping region sizes that can be supported by an
 * IARR
 */
#define MAX_NUM_IB_REGION_SIZES      9

#define IMAP_VALID_SHIFT             0
#define IMAP_VALID                   BIT(IMAP_VALID_SHIFT)

#define PCI_EXP_CAP                     0xac

#define IPROC_PCIE_REG_INVALID 0xffff

/**
 * iProc PCIe outbound mapping controller specific parameters
 *
 * @window_sizes: list of supported outbound mapping window sizes in MB
 * @nr_sizes: number of supported outbound mapping window sizes
 */
struct iproc_pcie_ob_map {
        resource_size_t window_sizes[MAX_NUM_OB_WINDOW_SIZES];
        unsigned int nr_sizes;
};

static const struct iproc_pcie_ob_map paxb_ob_map[] = {
        {
                /* OARR0/OMAP0 */
                .window_sizes = { 128, 256 },
                .nr_sizes = 2,
        },
        {
                /* OARR1/OMAP1 */
                .window_sizes = { 128, 256 },
                .nr_sizes = 2,
        },
};

static const struct iproc_pcie_ob_map paxb_v2_ob_map[] = {
        {
                /* OARR0/OMAP0 */
                .window_sizes = { 128, 256 },
                .nr_sizes = 2,
        },
        {
                /* OARR1/OMAP1 */
                .window_sizes = { 128, 256 },
                .nr_sizes = 2,
        },
        {
                /* OARR2/OMAP2 */
                .window_sizes = { 128, 256, 512, 1024 },
                .nr_sizes = 4,
        },
        {
                /* OARR3/OMAP3 */
                .window_sizes = { 128, 256, 512, 1024 },
                .nr_sizes = 4,
        },
};

/**
 * iProc PCIe inbound mapping type
 */
enum iproc_pcie_ib_map_type {
        /* for DDR memory */
        IPROC_PCIE_IB_MAP_MEM = 0,

        /* for device I/O memory */
        IPROC_PCIE_IB_MAP_IO,

        /* invalid or unused */
        IPROC_PCIE_IB_MAP_INVALID
};

/**
 * iProc PCIe inbound mapping controller specific parameters
 *
 * @type: inbound mapping region type
 * @size_unit: inbound mapping region size unit, could be SZ_1K, SZ_1M, or
 * SZ_1G
 * @region_sizes: list of supported inbound mapping region sizes in KB, MB, or
 * GB, depedning on the size unit
 * @nr_sizes: number of supported inbound mapping region sizes
 * @nr_windows: number of supported inbound mapping windows for the region
 * @imap_addr_offset: register offset between the upper and lower 32-bit
 * IMAP address registers
 * @imap_window_offset: register offset between each IMAP window
 */
struct iproc_pcie_ib_map {
        enum iproc_pcie_ib_map_type type;
        unsigned int size_unit;
        resource_size_t region_sizes[MAX_NUM_IB_REGION_SIZES];
        unsigned int nr_sizes;
        unsigned int nr_windows;
        u16 imap_addr_offset;
        u16 imap_window_offset;
};

static const struct iproc_pcie_ib_map paxb_v2_ib_map[] = {
        {
                /* IARR0/IMAP0 */
                .type = IPROC_PCIE_IB_MAP_IO,
                .size_unit = SZ_1K,
                .region_sizes = { 32 },
                .nr_sizes = 1,
                .nr_windows = 8,
                .imap_addr_offset = 0x40,
                .imap_window_offset = 0x4,
        },
        {
                /* IARR1/IMAP1 (currently unused) */
                .type = IPROC_PCIE_IB_MAP_INVALID,
        },
        {
                /* IARR2/IMAP2 */
                .type = IPROC_PCIE_IB_MAP_MEM,
                .size_unit = SZ_1M,
                .region_sizes = { 64, 128, 256, 512, 1024, 2048, 4096, 8192,
                                  16384 },
                .nr_sizes = 9,
                .nr_windows = 1,
                .imap_addr_offset = 0x4,
                .imap_window_offset = 0x8,
        },
        {
                /* IARR3/IMAP3 */
                .type = IPROC_PCIE_IB_MAP_MEM,
                .size_unit = SZ_1G,
                .region_sizes = { 1, 2, 4, 8, 16, 32 },
                .nr_sizes = 6,
                .nr_windows = 8,
                .imap_addr_offset = 0x4,
                .imap_window_offset = 0x8,
        },
        {
                /* IARR4/IMAP4 */
                .type = IPROC_PCIE_IB_MAP_MEM,
                .size_unit = SZ_1G,
                .region_sizes = { 32, 64, 128, 256, 512 },
                .nr_sizes = 5,
                .nr_windows = 8,
                .imap_addr_offset = 0x4,
                .imap_window_offset = 0x8,
        },
};

/*
 * iProc PCIe host registers
 */
enum iproc_pcie_reg {
        /* clock/reset signal control */
        IPROC_PCIE_CLK_CTRL = 0,

        /*
         * To allow MSI to be steered to an external MSI controller (e.g., ARM
         * GICv3 ITS)
         */
        IPROC_PCIE_MSI_GIC_MODE,

        /*
         * IPROC_PCIE_MSI_BASE_ADDR and IPROC_PCIE_MSI_WINDOW_SIZE define the
         * window where the MSI posted writes are written, for the writes to be
         * interpreted as MSI writes.
         */
        IPROC_PCIE_MSI_BASE_ADDR,
        IPROC_PCIE_MSI_WINDOW_SIZE,

        /*
         * To hold the address of the register where the MSI writes are
         * programed.  When ARM GICv3 ITS is used, this should be programmed
         * with the address of the GITS_TRANSLATER register.
         */
        IPROC_PCIE_MSI_ADDR_LO,
        IPROC_PCIE_MSI_ADDR_HI,

        /* enable MSI */
        IPROC_PCIE_MSI_EN_CFG,

        /* allow access to root complex configuration space */
        IPROC_PCIE_CFG_IND_ADDR,
        IPROC_PCIE_CFG_IND_DATA,

        /* allow access to device configuration space */
        IPROC_PCIE_CFG_ADDR,
        IPROC_PCIE_CFG_DATA,

        /* enable INTx */
        IPROC_PCIE_INTX_EN,

        /* outbound address mapping */
        IPROC_PCIE_OARR0,
        IPROC_PCIE_OMAP0,
        IPROC_PCIE_OARR1,
        IPROC_PCIE_OMAP1,
        IPROC_PCIE_OARR2,
        IPROC_PCIE_OMAP2,
        IPROC_PCIE_OARR3,
        IPROC_PCIE_OMAP3,

        /* inbound address mapping */
        IPROC_PCIE_IARR0,
        IPROC_PCIE_IMAP0,
        IPROC_PCIE_IARR1,
        IPROC_PCIE_IMAP1,
        IPROC_PCIE_IARR2,
        IPROC_PCIE_IMAP2,
        IPROC_PCIE_IARR3,
        IPROC_PCIE_IMAP3,
        IPROC_PCIE_IARR4,
        IPROC_PCIE_IMAP4,

        /* link status */
        IPROC_PCIE_LINK_STATUS,

        /* enable APB error for unsupported requests */
        IPROC_PCIE_APB_ERR_EN,

        /* total number of core registers */
        IPROC_PCIE_MAX_NUM_REG,
};

/* iProc PCIe PAXB BCMA registers */
static const u16 iproc_pcie_reg_paxb_bcma[] = {
        [IPROC_PCIE_CLK_CTRL]         = 0x000,
        [IPROC_PCIE_CFG_IND_ADDR]     = 0x120,
        [IPROC_PCIE_CFG_IND_DATA]     = 0x124,
        [IPROC_PCIE_CFG_ADDR]         = 0x1f8,
        [IPROC_PCIE_CFG_DATA]         = 0x1fc,
        [IPROC_PCIE_INTX_EN]          = 0x330,
        [IPROC_PCIE_LINK_STATUS]      = 0xf0c,
};

/* iProc PCIe PAXB registers */
static const u16 iproc_pcie_reg_paxb[] = {
        [IPROC_PCIE_CLK_CTRL]         = 0x000,
        [IPROC_PCIE_CFG_IND_ADDR]     = 0x120,
        [IPROC_PCIE_CFG_IND_DATA]     = 0x124,
        [IPROC_PCIE_CFG_ADDR]         = 0x1f8,
        [IPROC_PCIE_CFG_DATA]         = 0x1fc,
        [IPROC_PCIE_INTX_EN]          = 0x330,
        [IPROC_PCIE_OARR0]            = 0xd20,
        [IPROC_PCIE_OMAP0]            = 0xd40,
        [IPROC_PCIE_OARR1]            = 0xd28,
        [IPROC_PCIE_OMAP1]            = 0xd48,
        [IPROC_PCIE_LINK_STATUS]      = 0xf0c,
        [IPROC_PCIE_APB_ERR_EN]       = 0xf40,
};

/* iProc PCIe PAXB v2 registers */
static const u16 iproc_pcie_reg_paxb_v2[] = {
        [IPROC_PCIE_CLK_CTRL]         = 0x000,
        [IPROC_PCIE_CFG_IND_ADDR]     = 0x120,
        [IPROC_PCIE_CFG_IND_DATA]     = 0x124,
        [IPROC_PCIE_CFG_ADDR]         = 0x1f8,
        [IPROC_PCIE_CFG_DATA]         = 0x1fc,
        [IPROC_PCIE_INTX_EN]          = 0x330,
        [IPROC_PCIE_OARR0]            = 0xd20,
        [IPROC_PCIE_OMAP0]            = 0xd40,
        [IPROC_PCIE_OARR1]            = 0xd28,
        [IPROC_PCIE_OMAP1]            = 0xd48,
        [IPROC_PCIE_OARR2]            = 0xd60,
        [IPROC_PCIE_OMAP2]            = 0xd68,
        [IPROC_PCIE_OARR3]            = 0xdf0,
        [IPROC_PCIE_OMAP3]            = 0xdf8,
        [IPROC_PCIE_IARR0]            = 0xd00,
        [IPROC_PCIE_IMAP0]            = 0xc00,
        [IPROC_PCIE_IARR2]            = 0xd10,
        [IPROC_PCIE_IMAP2]            = 0xcc0,
        [IPROC_PCIE_IARR3]            = 0xe00,
        [IPROC_PCIE_IMAP3]            = 0xe08,
        [IPROC_PCIE_IARR4]            = 0xe68,
        [IPROC_PCIE_IMAP4]            = 0xe70,
        [IPROC_PCIE_LINK_STATUS]      = 0xf0c,
        [IPROC_PCIE_APB_ERR_EN]       = 0xf40,
};

/* iProc PCIe PAXC v1 registers */
static const u16 iproc_pcie_reg_paxc[] = {
        [IPROC_PCIE_CLK_CTRL]         = 0x000,
        [IPROC_PCIE_CFG_IND_ADDR]     = 0x1f0,
        [IPROC_PCIE_CFG_IND_DATA]     = 0x1f4,
        [IPROC_PCIE_CFG_ADDR]         = 0x1f8,
        [IPROC_PCIE_CFG_DATA]         = 0x1fc,
};

/* iProc PCIe PAXC v2 registers */
static const u16 iproc_pcie_reg_paxc_v2[] = {
        [IPROC_PCIE_MSI_GIC_MODE]     = 0x050,
        [IPROC_PCIE_MSI_BASE_ADDR]    = 0x074,
        [IPROC_PCIE_MSI_WINDOW_SIZE]  = 0x078,
        [IPROC_PCIE_MSI_ADDR_LO]      = 0x07c,
        [IPROC_PCIE_MSI_ADDR_HI]      = 0x080,
        [IPROC_PCIE_MSI_EN_CFG]       = 0x09c,
        [IPROC_PCIE_CFG_IND_ADDR]     = 0x1f0,
        [IPROC_PCIE_CFG_IND_DATA]     = 0x1f4,
        [IPROC_PCIE_CFG_ADDR]         = 0x1f8,
        [IPROC_PCIE_CFG_DATA]         = 0x1fc,
};

static inline struct iproc_pcie *iproc_data(struct pci_bus *bus)
{
        struct iproc_pcie *pcie;
#ifdef CONFIG_ARM
        struct pci_sys_data *sys = bus->sysdata;

        pcie = sys->private_data;
#else
        pcie = bus->sysdata;
#endif
        return pcie;
}

static inline bool iproc_pcie_reg_is_invalid(u16 reg_offset)
{
        return !!(reg_offset == IPROC_PCIE_REG_INVALID);
}

static inline u16 iproc_pcie_reg_offset(struct iproc_pcie *pcie,
                                        enum iproc_pcie_reg reg)
{
        return pcie->reg_offsets[reg];
}

static inline u32 iproc_pcie_read_reg(struct iproc_pcie *pcie,
                                      enum iproc_pcie_reg reg)
{
        u16 offset = iproc_pcie_reg_offset(pcie, reg);

        if (iproc_pcie_reg_is_invalid(offset))
                return 0;

        return readl(pcie->base + offset);
}

static inline void iproc_pcie_write_reg(struct iproc_pcie *pcie,
                                        enum iproc_pcie_reg reg, u32 val)
{
        u16 offset = iproc_pcie_reg_offset(pcie, reg);

        if (iproc_pcie_reg_is_invalid(offset))
                return;

        writel(val, pcie->base + offset);
}

/**
 * APB error forwarding can be disabled during access of configuration
 * registers of the endpoint device, to prevent unsupported requests
 * (typically seen during enumeration with multi-function devices) from
 * triggering a system exception.
 */
static inline void iproc_pcie_apb_err_disable(struct pci_bus *bus,
                                              bool disable)
{
        struct iproc_pcie *pcie = iproc_data(bus);
        u32 val;

        if (bus->number && pcie->has_apb_err_disable) {
                val = iproc_pcie_read_reg(pcie, IPROC_PCIE_APB_ERR_EN);
                if (disable)
                        val &= ~APB_ERR_EN;
                else
                        val |= APB_ERR_EN;
                iproc_pcie_write_reg(pcie, IPROC_PCIE_APB_ERR_EN, val);
        }
}

/**
 * Note access to the configuration registers are protected at the higher layer
 * by 'pci_lock' in drivers/pci/access.c
 */
static void __iomem *iproc_pcie_map_cfg_bus(struct iproc_pcie *pcie,
                                            int busno,
                                            unsigned int devfn,
                                            int where)
{
        unsigned slot = PCI_SLOT(devfn);
        unsigned fn = PCI_FUNC(devfn);
        u32 val;
        u16 offset;

        /* root complex access */
        if (busno == 0) {
                if (slot > 0 || fn > 0)
                        return NULL;

                iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_IND_ADDR,
                                     where & CFG_IND_ADDR_MASK);
                offset = iproc_pcie_reg_offset(pcie, IPROC_PCIE_CFG_IND_DATA);
                if (iproc_pcie_reg_is_invalid(offset))
                        return NULL;
                else
                        return (pcie->base + offset);
        }

        /*
         * PAXC is connected to an internally emulated EP within the SoC.  It
         * allows only one device.
         */
        if (pcie->ep_is_internal)
                if (slot > 0)
                        return NULL;

        /* EP device access */
        val = (busno << CFG_ADDR_BUS_NUM_SHIFT) |
                (slot << CFG_ADDR_DEV_NUM_SHIFT) |
                (fn << CFG_ADDR_FUNC_NUM_SHIFT) |
                (where & CFG_ADDR_REG_NUM_MASK) |
                (1 & CFG_ADDR_CFG_TYPE_MASK);
        iproc_pcie_write_reg(pcie, IPROC_PCIE_CFG_ADDR, val);
        offset = iproc_pcie_reg_offset(pcie, IPROC_PCIE_CFG_DATA);
        if (iproc_pcie_reg_is_invalid(offset))
                return NULL;
        else
                return (pcie->base + offset);
}

static void __iomem *iproc_pcie_bus_map_cfg_bus(struct pci_bus *bus,
                                                unsigned int devfn,
                                                int where)
{
        return iproc_pcie_map_cfg_bus(iproc_data(bus), bus->number, devfn,
                                      where);
}

static int iproc_pci_raw_config_read32(struct iproc_pcie *pcie,
                                       unsigned int devfn, int where,
                                       int size, u32 *val)
{
        void __iomem *addr;

        addr = iproc_pcie_map_cfg_bus(pcie, 0, devfn, where & ~0x3);
        if (!addr) {
                *val = ~0;
                return PCIBIOS_DEVICE_NOT_FOUND;
        }

        *val = readl(addr);

        if (size <= 2)
                *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);

        return PCIBIOS_SUCCESSFUL;
}

static int iproc_pci_raw_config_write32(struct iproc_pcie *pcie,
                                        unsigned int devfn, int where,
                                        int size, u32 val)
{
        void __iomem *addr;
        u32 mask, tmp;

        addr = iproc_pcie_map_cfg_bus(pcie, 0, devfn, where & ~0x3);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;

        if (size == 4) {
                writel(val, addr);
                return PCIBIOS_SUCCESSFUL;
        }

        mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8));
        tmp = readl(addr) & mask;
        tmp |= val << ((where & 0x3) * 8);
        writel(tmp, addr);

        return PCIBIOS_SUCCESSFUL;
}

static int iproc_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
                                    int where, int size, u32 *val)
{
        int ret;

        iproc_pcie_apb_err_disable(bus, true);
        ret = pci_generic_config_read32(bus, devfn, where, size, val);
        iproc_pcie_apb_err_disable(bus, false);

        return ret;
}

static int iproc_pcie_config_write32(struct pci_bus *bus, unsigned int devfn,
                                     int where, int size, u32 val)
{
        int ret;

        iproc_pcie_apb_err_disable(bus, true);
        ret = pci_generic_config_write32(bus, devfn, where, size, val);
        iproc_pcie_apb_err_disable(bus, false);

        return ret;
}

static struct pci_ops iproc_pcie_ops = {
        .map_bus = iproc_pcie_bus_map_cfg_bus,
        .read = iproc_pcie_config_read32,
        .write = iproc_pcie_config_write32,
};

static void iproc_pcie_reset(struct iproc_pcie *pcie)
{
        u32 val;

        /*
         * PAXC and the internal emulated endpoint device downstream should not
         * be reset.  If firmware has been loaded on the endpoint device at an
         * earlier boot stage, reset here causes issues.
         */
        if (pcie->ep_is_internal)
                return;

        /*
         * Select perst_b signal as reset source. Put the device into reset,
         * and then bring it out of reset
         */
        val = iproc_pcie_read_reg(pcie, IPROC_PCIE_CLK_CTRL);
        val &= ~EP_PERST_SOURCE_SELECT & ~EP_MODE_SURVIVE_PERST &
                ~RC_PCIE_RST_OUTPUT;
        iproc_pcie_write_reg(pcie, IPROC_PCIE_CLK_CTRL, val);
        udelay(250);

        val |= RC_PCIE_RST_OUTPUT;
        iproc_pcie_write_reg(pcie, IPROC_PCIE_CLK_CTRL, val);
        msleep(100);
}

static int iproc_pcie_check_link(struct iproc_pcie *pcie)
{
        struct device *dev = pcie->dev;
        u32 hdr_type, link_ctrl, link_status, class, val;
        u16 pos = PCI_EXP_CAP;
        bool link_is_active = false;

        /*
         * PAXC connects to emulated endpoint devices directly and does not
         * have a Serdes.  Therefore skip the link detection logic here.
         */
        if (pcie->ep_is_internal)
                return 0;

        val = iproc_pcie_read_reg(pcie, IPROC_PCIE_LINK_STATUS);
        if (!(val & PCIE_PHYLINKUP) || !(val & PCIE_DL_ACTIVE)) {
                dev_err(dev, "PHY or data link is INACTIVE!\n");
                return -ENODEV;
        }

        /* make sure we are not in EP mode */
        iproc_pci_raw_config_read32(pcie,  0, PCI_HEADER_TYPE, 1, &hdr_type);
        if ((hdr_type & 0x7f) != PCI_HEADER_TYPE_BRIDGE) {
                dev_err(dev, "in EP mode, hdr=%#02x\n", hdr_type);
                return -EFAULT;
        }

        /* force class to PCI_CLASS_BRIDGE_PCI (0x0604) */
#define PCI_BRIDGE_CTRL_REG_OFFSET 0x43c
#define PCI_CLASS_BRIDGE_MASK      0xffff00
#define PCI_CLASS_BRIDGE_SHIFT     8
        iproc_pci_raw_config_read32(pcie, 0, PCI_BRIDGE_CTRL_REG_OFFSET,
                                    4, &class);
        class &= ~PCI_CLASS_BRIDGE_MASK;
        class |= (PCI_CLASS_BRIDGE_PCI << PCI_CLASS_BRIDGE_SHIFT);
        iproc_pci_raw_config_write32(pcie, 0, PCI_BRIDGE_CTRL_REG_OFFSET,
                                     4, class);

        /* check link status to see if link is active */
        iproc_pci_raw_config_read32(pcie, 0, pos + PCI_EXP_LNKSTA,
                                    2, &link_status);
        if (link_status & PCI_EXP_LNKSTA_NLW)
                link_is_active = true;

        if (!link_is_active) {
                /* try GEN 1 link speed */
#define PCI_TARGET_LINK_SPEED_MASK    0xf
#define PCI_TARGET_LINK_SPEED_GEN2    0x2
#define PCI_TARGET_LINK_SPEED_GEN1    0x1
                iproc_pci_raw_config_read32(pcie, 0,
                                          pos + PCI_EXP_LNKCTL2, 4,
                                          &link_ctrl);
                if ((link_ctrl & PCI_TARGET_LINK_SPEED_MASK) ==
                    PCI_TARGET_LINK_SPEED_GEN2) {
                        link_ctrl &= ~PCI_TARGET_LINK_SPEED_MASK;
                        link_ctrl |= PCI_TARGET_LINK_SPEED_GEN1;
                        iproc_pci_raw_config_write32(pcie, 0,
                                                pos + PCI_EXP_LNKCTL2,
                                                4, link_ctrl);
                        msleep(100);

                        iproc_pci_raw_config_read32(pcie, 0,
                                                pos + PCI_EXP_LNKSTA,
                                                2, &link_status);
                        if (link_status & PCI_EXP_LNKSTA_NLW)
                                link_is_active = true;
                }
        }

        dev_info(dev, "link: %s\n", link_is_active ? "UP" : "DOWN");

        return link_is_active ? 0 : -ENODEV;
}

static void iproc_pcie_enable(struct iproc_pcie *pcie)
{
        iproc_pcie_write_reg(pcie, IPROC_PCIE_INTX_EN, SYS_RC_INTX_MASK);
}

static inline bool iproc_pcie_ob_is_valid(struct iproc_pcie *pcie,
                                          int window_idx)
{
        u32 val;

        val = iproc_pcie_read_reg(pcie, MAP_REG(IPROC_PCIE_OARR0, window_idx));

        return !!(val & OARR_VALID);
}

static inline int iproc_pcie_ob_write(struct iproc_pcie *pcie, int window_idx,
                                      int size_idx, u64 axi_addr, u64 pci_addr)
{
        struct device *dev = pcie->dev;
        u16 oarr_offset, omap_offset;

        /*
         * Derive the OARR/OMAP offset from the first pair (OARR0/OMAP0) based
         * on window index.
         */
        oarr_offset = iproc_pcie_reg_offset(pcie, MAP_REG(IPROC_PCIE_OARR0,
                                                          window_idx));
        omap_offset = iproc_pcie_reg_offset(pcie, MAP_REG(IPROC_PCIE_OMAP0,
                                                          window_idx));
        if (iproc_pcie_reg_is_invalid(oarr_offset) ||
            iproc_pcie_reg_is_invalid(omap_offset))
                return -EINVAL;

        /*
         * Program the OARR registers.  The upper 32-bit OARR register is
         * always right after the lower 32-bit OARR register.
         */
        writel(lower_32_bits(axi_addr) | (size_idx << OARR_SIZE_CFG_SHIFT) |
               OARR_VALID, pcie->base + oarr_offset);
        writel(upper_32_bits(axi_addr), pcie->base + oarr_offset + 4);

        /* now program the OMAP registers */
        writel(lower_32_bits(pci_addr), pcie->base + omap_offset);
        writel(upper_32_bits(pci_addr), pcie->base + omap_offset + 4);

        dev_info(dev, "ob window [%d]: offset 0x%x axi %pap pci %pap\n",
                 window_idx, oarr_offset, &axi_addr, &pci_addr);
        dev_info(dev, "oarr lo 0x%x oarr hi 0x%x\n",
                 readl(pcie->base + oarr_offset),
                 readl(pcie->base + oarr_offset + 4));
        dev_info(dev, "omap lo 0x%x omap hi 0x%x\n",
                 readl(pcie->base + omap_offset),
                 readl(pcie->base + omap_offset + 4));

        return 0;
}

/**
 * Some iProc SoCs require the SW to configure the outbound address mapping
 *
 * Outbound address translation:
 *
 * iproc_pcie_address = axi_address - axi_offset
 * OARR = iproc_pcie_address
 * OMAP = pci_addr
 *
 * axi_addr -> iproc_pcie_address -> OARR -> OMAP -> pci_address
 */
static int iproc_pcie_setup_ob(struct iproc_pcie *pcie, u64 axi_addr,
                               u64 pci_addr, resource_size_t size)
{
        struct iproc_pcie_ob *ob = &pcie->ob;
        struct device *dev = pcie->dev;
        int ret = -EINVAL, window_idx, size_idx;

        if (axi_addr < ob->axi_offset) {
                dev_err(dev, "axi address %pap less than offset %pap\n",
                        &axi_addr, &ob->axi_offset);
                return -EINVAL;
        }

        /*
         * Translate the AXI address to the internal address used by the iProc
         * PCIe core before programming the OARR
         */
        axi_addr -= ob->axi_offset;

        /* iterate through all OARR/OMAP mapping windows */
        for (window_idx = ob->nr_windows - 1; window_idx >= 0; window_idx--) {
                const struct iproc_pcie_ob_map *ob_map =
                        &pcie->ob_map[window_idx];

                /*
                 * If current outbound window is already in use, move on to the
                 * next one.
                 */
                if (iproc_pcie_ob_is_valid(pcie, window_idx))
                        continue;

                /*
                 * Iterate through all supported window sizes within the
                 * OARR/OMAP pair to find a match.  Go through the window sizes
                 * in a descending order.
                 */
                for (size_idx = ob_map->nr_sizes - 1; size_idx >= 0;
                     size_idx--) {
                        resource_size_t window_size =
                                ob_map->window_sizes[size_idx] * SZ_1M;

                        if (size < window_size)
                                continue;

                        if (!IS_ALIGNED(axi_addr, window_size) ||
                            !IS_ALIGNED(pci_addr, window_size)) {
                                dev_err(dev,
                                        "axi %pap or pci %pap not aligned\n",
                                        &axi_addr, &pci_addr);
                                return -EINVAL;
                        }

                        /*
                         * Match found!  Program both OARR and OMAP and mark
                         * them as a valid entry.
                         */
                        ret = iproc_pcie_ob_write(pcie, window_idx, size_idx,
                                                  axi_addr, pci_addr);
                        if (ret)
                                goto err_ob;

                        size -= window_size;
                        if (size == 0)
                                return 0;

                        /*
                         * If we are here, we are done with the current window,
                         * but not yet finished all mappings.  Need to move on
                         * to the next window.
                         */
                        axi_addr += window_size;
                        pci_addr += window_size;
                        break;
                }
        }

err_ob:
        dev_err(dev, "unable to configure outbound mapping\n");
        dev_err(dev,
                "axi %pap, axi offset %pap, pci %pap, res size %pap\n",
                &axi_addr, &ob->axi_offset, &pci_addr, &size);

        return ret;
}

static int iproc_pcie_map_ranges(struct iproc_pcie *pcie,
                                 struct list_head *resources)
{
        struct device *dev = pcie->dev;
        struct resource_entry *window;
        int ret;

        resource_list_for_each_entry(window, resources) {
                struct resource *res = window->res;
                u64 res_type = resource_type(res);

                switch (res_type) {
                case IORESOURCE_IO:
                case IORESOURCE_BUS:
                        break;
                case IORESOURCE_MEM:
                        ret = iproc_pcie_setup_ob(pcie, res->start,
                                                  res->start - window->offset,
                                                  resource_size(res));
                        if (ret)
                                return ret;
                        break;
                default:
                        dev_err(dev, "invalid resource %pR\n", res);
                        return -EINVAL;
                }
        }

        return 0;
}

static inline bool iproc_pcie_ib_is_in_use(struct iproc_pcie *pcie,
                                           int region_idx)
{
        const struct iproc_pcie_ib_map *ib_map = &pcie->ib_map[region_idx];
        u32 val;

        val = iproc_pcie_read_reg(pcie, MAP_REG(IPROC_PCIE_IARR0, region_idx));

        return !!(val & (BIT(ib_map->nr_sizes) - 1));
}

static inline bool iproc_pcie_ib_check_type(const struct iproc_pcie_ib_map *ib_map,
                                            enum iproc_pcie_ib_map_type type)
{
        return !!(ib_map->type == type);
}

static int iproc_pcie_ib_write(struct iproc_pcie *pcie, int region_idx,
                               int size_idx, int nr_windows, u64 axi_addr,
                               u64 pci_addr, resource_size_t size)
{
        struct device *dev = pcie->dev;
        const struct iproc_pcie_ib_map *ib_map = &pcie->ib_map[region_idx];
        u16 iarr_offset, imap_offset;
        u32 val;
        int window_idx;

        iarr_offset = iproc_pcie_reg_offset(pcie,
                                MAP_REG(IPROC_PCIE_IARR0, region_idx));
        imap_offset = iproc_pcie_reg_offset(pcie,
                                MAP_REG(IPROC_PCIE_IMAP0, region_idx));
        if (iproc_pcie_reg_is_invalid(iarr_offset) ||
            iproc_pcie_reg_is_invalid(imap_offset))
                return -EINVAL;

        dev_info(dev, "ib region [%d]: offset 0x%x axi %pap pci %pap\n",
                 region_idx, iarr_offset, &axi_addr, &pci_addr);

        /*
         * Program the IARR registers.  The upper 32-bit IARR register is
         * always right after the lower 32-bit IARR register.
         */
        writel(lower_32_bits(pci_addr) | BIT(size_idx),
               pcie->base + iarr_offset);
        writel(upper_32_bits(pci_addr), pcie->base + iarr_offset + 4);

        dev_info(dev, "iarr lo 0x%x iarr hi 0x%x\n",
                 readl(pcie->base + iarr_offset),
                 readl(pcie->base + iarr_offset + 4));

        /*
         * Now program the IMAP registers.  Each IARR region may have one or
         * more IMAP windows.
         */
        size >>= ilog2(nr_windows);
        for (window_idx = 0; window_idx < nr_windows; window_idx++) {
                val = readl(pcie->base + imap_offset);
                val |= lower_32_bits(axi_addr) | IMAP_VALID;
                writel(val, pcie->base + imap_offset);
                writel(upper_32_bits(axi_addr),
                       pcie->base + imap_offset + ib_map->imap_addr_offset);

                dev_info(dev, "imap window [%d] lo 0x%x hi 0x%x\n",
                         window_idx, readl(pcie->base + imap_offset),
                         readl(pcie->base + imap_offset +
                               ib_map->imap_addr_offset));

                imap_offset += ib_map->imap_window_offset;
                axi_addr += size;
        }

        return 0;
}

static int iproc_pcie_setup_ib(struct iproc_pcie *pcie,
                               struct of_pci_range *range,
                               enum iproc_pcie_ib_map_type type)
{
        struct device *dev = pcie->dev;
        struct iproc_pcie_ib *ib = &pcie->ib;
        int ret;
        unsigned int region_idx, size_idx;
        u64 axi_addr = range->cpu_addr, pci_addr = range->pci_addr;
        resource_size_t size = range->size;

        /* iterate through all IARR mapping regions */
        for (region_idx = 0; region_idx < ib->nr_regions; region_idx++) {
                const struct iproc_pcie_ib_map *ib_map =
                        &pcie->ib_map[region_idx];

                /*
                 * If current inbound region is already in use or not a
                 * compatible type, move on to the next.
                 */
                if (iproc_pcie_ib_is_in_use(pcie, region_idx) ||
                    !iproc_pcie_ib_check_type(ib_map, type))
                        continue;

                /* iterate through all supported region sizes to find a match */
                for (size_idx = 0; size_idx < ib_map->nr_sizes; size_idx++) {
                        resource_size_t region_size =
                        ib_map->region_sizes[size_idx] * ib_map->size_unit;

                        if (size != region_size)
                                continue;

                        if (!IS_ALIGNED(axi_addr, region_size) ||
                            !IS_ALIGNED(pci_addr, region_size)) {
                                dev_err(dev,
                                        "axi %pap or pci %pap not aligned\n",
                                        &axi_addr, &pci_addr);
                                return -EINVAL;
                        }

                        /* Match found!  Program IARR and all IMAP windows. */
                        ret = iproc_pcie_ib_write(pcie, region_idx, size_idx,
                                                  ib_map->nr_windows, axi_addr,
                                                  pci_addr, size);
                        if (ret)
                                goto err_ib;
                        else
                                return 0;

                }
        }
        ret = -EINVAL;

err_ib:
        dev_err(dev, "unable to configure inbound mapping\n");
        dev_err(dev, "axi %pap, pci %pap, res size %pap\n",
                &axi_addr, &pci_addr, &size);

        return ret;

}

static int pci_dma_range_parser_init(struct of_pci_range_parser *parser,
                                     struct device_node *node)
{
        const int na = 3, ns = 2;
        int rlen;

        parser->node = node;
        parser->pna = of_n_addr_cells(node);
        parser->np = parser->pna + na + ns;

        parser->range = of_get_property(node, "dma-ranges", &rlen);
        if (!parser->range)
                return -ENOENT;

        parser->end = parser->range + rlen / sizeof(__be32);
        return 0;
}

static int iproc_pcie_map_dma_ranges(struct iproc_pcie *pcie)
{
        struct of_pci_range range;
        struct of_pci_range_parser parser;
        int ret;

        /* Get the dma-ranges from DT */
        ret = pci_dma_range_parser_init(&parser, pcie->dev->of_node);
        if (ret)
                return ret;

        for_each_of_pci_range(&parser, &range) {
                /* Each range entry corresponds to an inbound mapping region */
                ret = iproc_pcie_setup_ib(pcie, &range, IPROC_PCIE_IB_MAP_MEM);
                if (ret)
                        return ret;
        }

        return 0;
}

static int iproce_pcie_get_msi(struct iproc_pcie *pcie,
                               struct device_node *msi_node,
                               u64 *msi_addr)
{
        struct device *dev = pcie->dev;
        int ret;
        struct resource res;

        /*
         * Check if 'msi-map' points to ARM GICv3 ITS, which is the only
         * supported external MSI controller that requires steering.
         */
        if (!of_device_is_compatible(msi_node, "arm,gic-v3-its")) {
                dev_err(dev, "unable to find compatible MSI controller\n");
                return -ENODEV;
        }

        /* derive GITS_TRANSLATER address from GICv3 */
        ret = of_address_to_resource(msi_node, 0, &res);
        if (ret < 0) {
                dev_err(dev, "unable to obtain MSI controller resources\n");
                return ret;
        }

        *msi_addr = res.start + GITS_TRANSLATER;
        return 0;
}

static int iproc_pcie_paxb_v2_msi_steer(struct iproc_pcie *pcie, u64 msi_addr)
{
        int ret;
        struct of_pci_range range;

        memset(&range, 0, sizeof(range));
        range.size = SZ_32K;
        range.pci_addr = range.cpu_addr = msi_addr & ~(range.size - 1);

        ret = iproc_pcie_setup_ib(pcie, &range, IPROC_PCIE_IB_MAP_IO);
        return ret;
}

static void iproc_pcie_paxc_v2_msi_steer(struct iproc_pcie *pcie, u64 msi_addr)
{
        u32 val;

        /*
         * Program bits [43:13] of address of GITS_TRANSLATER register into
         * bits [30:0] of the MSI base address register.  In fact, in all iProc
         * based SoCs, all I/O register bases are well below the 32-bit
         * boundary, so we can safely assume bits [43:32] are always zeros.
         */
        iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_BASE_ADDR,
                             (u32)(msi_addr >> 13));

        /* use a default 8K window size */
        iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_WINDOW_SIZE, 0);

        /* steering MSI to GICv3 ITS */
        val = iproc_pcie_read_reg(pcie, IPROC_PCIE_MSI_GIC_MODE);
        val |= GIC_V3_CFG;
        iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_GIC_MODE, val);

        /*
         * Program bits [43:2] of address of GITS_TRANSLATER register into the
         * iProc MSI address registers.
         */
        msi_addr >>= 2;
        iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_ADDR_HI,
                             upper_32_bits(msi_addr));
        iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_ADDR_LO,
                             lower_32_bits(msi_addr));

        /* enable MSI */
        val = iproc_pcie_read_reg(pcie, IPROC_PCIE_MSI_EN_CFG);
        val |= MSI_ENABLE_CFG;
        iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_EN_CFG, val);
}

static int iproc_pcie_msi_steer(struct iproc_pcie *pcie,
                                struct device_node *msi_node)
{
        struct device *dev = pcie->dev;
        int ret;
        u64 msi_addr;

        ret = iproce_pcie_get_msi(pcie, msi_node, &msi_addr);
        if (ret < 0) {
                dev_err(dev, "msi steering failed\n");
                return ret;
        }

        switch (pcie->type) {
        case IPROC_PCIE_PAXB_V2:
                ret = iproc_pcie_paxb_v2_msi_steer(pcie, msi_addr);
                if (ret)
                        return ret;
                break;
        case IPROC_PCIE_PAXC_V2:
                iproc_pcie_paxc_v2_msi_steer(pcie, msi_addr);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int iproc_pcie_msi_enable(struct iproc_pcie *pcie)
{
        struct device_node *msi_node;
        int ret;

        /*
         * Either the "msi-parent" or the "msi-map" phandle needs to exist
         * for us to obtain the MSI node.
         */

        msi_node = of_parse_phandle(pcie->dev->of_node, "msi-parent", 0);
        if (!msi_node) {
                const __be32 *msi_map = NULL;
                int len;
                u32 phandle;

                msi_map = of_get_property(pcie->dev->of_node, "msi-map", &len);
                if (!msi_map)
                        return -ENODEV;

                phandle = be32_to_cpup(msi_map + 1);
                msi_node = of_find_node_by_phandle(phandle);
                if (!msi_node)
                        return -ENODEV;
        }

        /*
         * Certain revisions of the iProc PCIe controller require additional
         * configurations to steer the MSI writes towards an external MSI
         * controller.
         */
        if (pcie->need_msi_steer) {
                ret = iproc_pcie_msi_steer(pcie, msi_node);
                if (ret)
                        return ret;
        }

        /*
         * If another MSI controller is being used, the call below should fail
         * but that is okay
         */
        return iproc_msi_init(pcie, msi_node);
}

static void iproc_pcie_msi_disable(struct iproc_pcie *pcie)
{
        iproc_msi_exit(pcie);
}

static int iproc_pcie_rev_init(struct iproc_pcie *pcie)
{
        struct device *dev = pcie->dev;
        unsigned int reg_idx;
        const u16 *regs;

        switch (pcie->type) {
        case IPROC_PCIE_PAXB_BCMA:
                regs = iproc_pcie_reg_paxb_bcma;
                break;
        case IPROC_PCIE_PAXB:
                regs = iproc_pcie_reg_paxb;
                pcie->has_apb_err_disable = true;
                if (pcie->need_ob_cfg) {
                        pcie->ob_map = paxb_ob_map;
                        pcie->ob.nr_windows = ARRAY_SIZE(paxb_ob_map);
                }
                break;
        case IPROC_PCIE_PAXB_V2:
                regs = iproc_pcie_reg_paxb_v2;
                pcie->has_apb_err_disable = true;
                if (pcie->need_ob_cfg) {
                        pcie->ob_map = paxb_v2_ob_map;
                        pcie->ob.nr_windows = ARRAY_SIZE(paxb_v2_ob_map);
                }
                pcie->ib.nr_regions = ARRAY_SIZE(paxb_v2_ib_map);
                pcie->ib_map = paxb_v2_ib_map;
                pcie->need_msi_steer = true;
                break;
        case IPROC_PCIE_PAXC:
                regs = iproc_pcie_reg_paxc;
                pcie->ep_is_internal = true;
                break;
        case IPROC_PCIE_PAXC_V2:
                regs = iproc_pcie_reg_paxc_v2;
                pcie->ep_is_internal = true;
                pcie->need_msi_steer = true;
                break;
        default:
                dev_err(dev, "incompatible iProc PCIe interface\n");
                return -EINVAL;
        }

        pcie->reg_offsets = devm_kcalloc(dev, IPROC_PCIE_MAX_NUM_REG,
                                         sizeof(*pcie->reg_offsets),
                                         GFP_KERNEL);
        if (!pcie->reg_offsets)
                return -ENOMEM;

        /* go through the register table and populate all valid registers */
        pcie->reg_offsets[0] = (pcie->type == IPROC_PCIE_PAXC_V2) ?
                IPROC_PCIE_REG_INVALID : regs[0];
        for (reg_idx = 1; reg_idx < IPROC_PCIE_MAX_NUM_REG; reg_idx++)
                pcie->reg_offsets[reg_idx] = regs[reg_idx] ?
                        regs[reg_idx] : IPROC_PCIE_REG_INVALID;

        return 0;
}

int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
{
        struct device *dev;
        int ret;
        void *sysdata;
        struct pci_bus *child;
        struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);

        dev = pcie->dev;

        ret = iproc_pcie_rev_init(pcie);
        if (ret) {
                dev_err(dev, "unable to initialize controller parameters\n");
                return ret;
        }

        ret = devm_request_pci_bus_resources(dev, res);
        if (ret)
                return ret;

        ret = phy_init(pcie->phy);
        if (ret) {
                dev_err(dev, "unable to initialize PCIe PHY\n");
                return ret;
        }

        ret = phy_power_on(pcie->phy);
        if (ret) {
                dev_err(dev, "unable to power on PCIe PHY\n");
                goto err_exit_phy;
        }

        iproc_pcie_reset(pcie);

        if (pcie->need_ob_cfg) {
                ret = iproc_pcie_map_ranges(pcie, res);
                if (ret) {
                        dev_err(dev, "map failed\n");
                        goto err_power_off_phy;
                }
        }

        ret = iproc_pcie_map_dma_ranges(pcie);
        if (ret && ret != -ENOENT)
                goto err_power_off_phy;

#ifdef CONFIG_ARM
        pcie->sysdata.private_data = pcie;
        sysdata = &pcie->sysdata;
#else
        sysdata = pcie;
#endif

        ret = iproc_pcie_check_link(pcie);
        if (ret) {
                dev_err(dev, "no PCIe EP device detected\n");
                goto err_power_off_phy;
        }

        iproc_pcie_enable(pcie);

        if (IS_ENABLED(CONFIG_PCI_MSI))
                if (iproc_pcie_msi_enable(pcie))
                        dev_info(dev, "not using iProc MSI\n");

        list_splice_init(res, &host->windows);
        host->busnr = 0;
        host->dev.parent = dev;
        host->ops = &iproc_pcie_ops;
        host->sysdata = sysdata;
        host->map_irq = pcie->map_irq;
        host->swizzle_irq = pci_common_swizzle;

        ret = pci_scan_root_bus_bridge(host);
        if (ret < 0) {
                dev_err(dev, "failed to scan host: %d\n", ret);
                goto err_power_off_phy;
        }

        pci_assign_unassigned_bus_resources(host->bus);

        pcie->root_bus = host->bus;

        list_for_each_entry(child, &host->bus->children, node)
                pcie_bus_configure_settings(child);

        pci_bus_add_devices(host->bus);

        return 0;

err_power_off_phy:
        phy_power_off(pcie->phy);
err_exit_phy:
        phy_exit(pcie->phy);
        return ret;
}
EXPORT_SYMBOL(iproc_pcie_setup);

int iproc_pcie_remove(struct iproc_pcie *pcie)
{
        pci_stop_root_bus(pcie->root_bus);
        pci_remove_root_bus(pcie->root_bus);

        iproc_pcie_msi_disable(pcie);

        phy_power_off(pcie->phy);
        phy_exit(pcie->phy);

        return 0;
}
EXPORT_SYMBOL(iproc_pcie_remove);

MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
MODULE_DESCRIPTION("Broadcom iPROC PCIe common driver");
MODULE_LICENSE("GPL v2");