// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for the Aardvark PCIe controller, used on Marvell Armada
 * 3700.
 *
 * Copyright (C) 2016 Marvell
 *
 * Author: Hezi Shahmoon <hezi.shahmoon@marvell.com>
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pci-ecam.h>
#include <linux/init.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/of_pci.h>

#include "../pci.h"
#include "../pci-bridge-emul.h"

/* PCIe core registers */
#define PCIE_CORE_DEV_ID_REG                                    0x0
#define PCIE_CORE_CMD_STATUS_REG                                0x4
#define     PCIE_CORE_CMD_IO_ACCESS_EN                          BIT(0)
#define     PCIE_CORE_CMD_MEM_ACCESS_EN                         BIT(1)
#define     PCIE_CORE_CMD_MEM_IO_REQ_EN                         BIT(2)
#define PCIE_CORE_DEV_REV_REG                                   0x8
#define PCIE_CORE_PCIEXP_CAP                                    0xc0
#define PCIE_CORE_ERR_CAPCTL_REG                                0x118
#define     PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX                    BIT(5)
#define     PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX_EN                 BIT(6)
#define     PCIE_CORE_ERR_CAPCTL_ECRC_CHCK                      BIT(7)
#define     PCIE_CORE_ERR_CAPCTL_ECRC_CHCK_RCV                  BIT(8)
#define     PCIE_CORE_INT_A_ASSERT_ENABLE                       1
#define     PCIE_CORE_INT_B_ASSERT_ENABLE                       2
#define     PCIE_CORE_INT_C_ASSERT_ENABLE                       3
#define     PCIE_CORE_INT_D_ASSERT_ENABLE                       4
/* PIO registers base address and register offsets */
#define PIO_BASE_ADDR                           0x4000
#define PIO_CTRL                                (PIO_BASE_ADDR + 0x0)
#define   PIO_CTRL_TYPE_MASK                    GENMASK(3, 0)
#define   PIO_CTRL_ADDR_WIN_DISABLE             BIT(24)
#define PIO_STAT                                (PIO_BASE_ADDR + 0x4)
#define   PIO_COMPLETION_STATUS_SHIFT           7
#define   PIO_COMPLETION_STATUS_MASK            GENMASK(9, 7)
#define   PIO_COMPLETION_STATUS_OK              0
#define   PIO_COMPLETION_STATUS_UR              1
#define   PIO_COMPLETION_STATUS_CRS             2
#define   PIO_COMPLETION_STATUS_CA              4
#define   PIO_NON_POSTED_REQ                    BIT(10)
#define   PIO_ERR_STATUS                        BIT(11)
#define PIO_ADDR_LS                             (PIO_BASE_ADDR + 0x8)
#define PIO_ADDR_MS                             (PIO_BASE_ADDR + 0xc)
#define PIO_WR_DATA                             (PIO_BASE_ADDR + 0x10)
#define PIO_WR_DATA_STRB                        (PIO_BASE_ADDR + 0x14)
#define PIO_RD_DATA                             (PIO_BASE_ADDR + 0x18)
#define PIO_START                               (PIO_BASE_ADDR + 0x1c)
#define PIO_ISR                                 (PIO_BASE_ADDR + 0x20)
#define PIO_ISRM                                (PIO_BASE_ADDR + 0x24)

/* Aardvark Control registers */
#define CONTROL_BASE_ADDR                       0x4800
#define PCIE_CORE_CTRL0_REG                     (CONTROL_BASE_ADDR + 0x0)
#define     PCIE_GEN_SEL_MSK                    0x3
#define     PCIE_GEN_SEL_SHIFT                  0x0
#define     SPEED_GEN_1                         0
#define     SPEED_GEN_2                         1
#define     SPEED_GEN_3                         2
#define     IS_RC_MSK                           1
#define     IS_RC_SHIFT                         2
#define     LANE_CNT_MSK                        0x18
#define     LANE_CNT_SHIFT                      0x3
#define     LANE_COUNT_1                        (0 << LANE_CNT_SHIFT)
#define     LANE_COUNT_2                        (1 << LANE_CNT_SHIFT)
#define     LANE_COUNT_4                        (2 << LANE_CNT_SHIFT)
#define     LANE_COUNT_8                        (3 << LANE_CNT_SHIFT)
#define     LINK_TRAINING_EN                    BIT(6)
#define     LEGACY_INTA                         BIT(28)
#define     LEGACY_INTB                         BIT(29)
#define     LEGACY_INTC                         BIT(30)
#define     LEGACY_INTD                         BIT(31)
#define PCIE_CORE_CTRL1_REG                     (CONTROL_BASE_ADDR + 0x4)
#define     HOT_RESET_GEN                       BIT(0)
#define PCIE_CORE_CTRL2_REG                     (CONTROL_BASE_ADDR + 0x8)
#define     PCIE_CORE_CTRL2_RESERVED            0x7
#define     PCIE_CORE_CTRL2_TD_ENABLE           BIT(4)
#define     PCIE_CORE_CTRL2_STRICT_ORDER_ENABLE BIT(5)
#define     PCIE_CORE_CTRL2_OB_WIN_ENABLE       BIT(6)
#define     PCIE_CORE_CTRL2_MSI_ENABLE          BIT(10)
#define PCIE_CORE_REF_CLK_REG                   (CONTROL_BASE_ADDR + 0x14)
#define     PCIE_CORE_REF_CLK_TX_ENABLE         BIT(1)
#define PCIE_MSG_LOG_REG                        (CONTROL_BASE_ADDR + 0x30)
#define PCIE_ISR0_REG                           (CONTROL_BASE_ADDR + 0x40)
#define PCIE_MSG_PM_PME_MASK                    BIT(7)
#define PCIE_ISR0_MASK_REG                      (CONTROL_BASE_ADDR + 0x44)
#define     PCIE_ISR0_MSI_INT_PENDING           BIT(24)
#define     PCIE_ISR0_INTX_ASSERT(val)          BIT(16 + (val))
#define     PCIE_ISR0_INTX_DEASSERT(val)        BIT(20 + (val))
#define     PCIE_ISR0_ALL_MASK                  GENMASK(26, 0)
#define PCIE_ISR1_REG                           (CONTROL_BASE_ADDR + 0x48)
#define PCIE_ISR1_MASK_REG                      (CONTROL_BASE_ADDR + 0x4C)
#define     PCIE_ISR1_POWER_STATE_CHANGE        BIT(4)
#define     PCIE_ISR1_FLUSH                     BIT(5)
#define     PCIE_ISR1_INTX_ASSERT(val)          BIT(8 + (val))
#define     PCIE_ISR1_ALL_MASK                  GENMASK(11, 4)
#define PCIE_MSI_ADDR_LOW_REG                   (CONTROL_BASE_ADDR + 0x50)
#define PCIE_MSI_ADDR_HIGH_REG                  (CONTROL_BASE_ADDR + 0x54)
#define PCIE_MSI_STATUS_REG                     (CONTROL_BASE_ADDR + 0x58)
#define PCIE_MSI_MASK_REG                       (CONTROL_BASE_ADDR + 0x5C)
#define PCIE_MSI_PAYLOAD_REG                    (CONTROL_BASE_ADDR + 0x9C)

/* PCIe window configuration */
#define OB_WIN_BASE_ADDR                        0x4c00
#define OB_WIN_BLOCK_SIZE                       0x20
#define OB_WIN_COUNT                            8
#define OB_WIN_REG_ADDR(win, offset)            (OB_WIN_BASE_ADDR + \
                                                 OB_WIN_BLOCK_SIZE * (win) + \
                                                 (offset))
#define OB_WIN_MATCH_LS(win)                    OB_WIN_REG_ADDR(win, 0x00)
#define     OB_WIN_ENABLE                       BIT(0)
#define OB_WIN_MATCH_MS(win)                    OB_WIN_REG_ADDR(win, 0x04)
#define OB_WIN_REMAP_LS(win)                    OB_WIN_REG_ADDR(win, 0x08)
#define OB_WIN_REMAP_MS(win)                    OB_WIN_REG_ADDR(win, 0x0c)
#define OB_WIN_MASK_LS(win)                     OB_WIN_REG_ADDR(win, 0x10)
#define OB_WIN_MASK_MS(win)                     OB_WIN_REG_ADDR(win, 0x14)
#define OB_WIN_ACTIONS(win)                     OB_WIN_REG_ADDR(win, 0x18)
#define OB_WIN_DEFAULT_ACTIONS                  (OB_WIN_ACTIONS(OB_WIN_COUNT-1) + 0x4)
#define     OB_WIN_FUNC_NUM_MASK                GENMASK(31, 24)
#define     OB_WIN_FUNC_NUM_SHIFT               24
#define     OB_WIN_FUNC_NUM_ENABLE              BIT(23)
#define     OB_WIN_BUS_NUM_BITS_MASK            GENMASK(22, 20)
#define     OB_WIN_BUS_NUM_BITS_SHIFT           20
#define     OB_WIN_MSG_CODE_ENABLE              BIT(22)
#define     OB_WIN_MSG_CODE_MASK                GENMASK(21, 14)
#define     OB_WIN_MSG_CODE_SHIFT               14
#define     OB_WIN_MSG_PAYLOAD_LEN              BIT(12)
#define     OB_WIN_ATTR_ENABLE                  BIT(11)
#define     OB_WIN_ATTR_TC_MASK                 GENMASK(10, 8)
#define     OB_WIN_ATTR_TC_SHIFT                8
#define     OB_WIN_ATTR_RELAXED                 BIT(7)
#define     OB_WIN_ATTR_NOSNOOP                 BIT(6)
#define     OB_WIN_ATTR_POISON                  BIT(5)
#define     OB_WIN_ATTR_IDO                     BIT(4)
#define     OB_WIN_TYPE_MASK                    GENMASK(3, 0)
#define     OB_WIN_TYPE_SHIFT                   0
#define     OB_WIN_TYPE_MEM                     0x0
#define     OB_WIN_TYPE_IO                      0x4
#define     OB_WIN_TYPE_CONFIG_TYPE0            0x8
#define     OB_WIN_TYPE_CONFIG_TYPE1            0x9
#define     OB_WIN_TYPE_MSG                     0xc

/* LMI registers base address and register offsets */
#define LMI_BASE_ADDR                           0x6000
#define CFG_REG                                 (LMI_BASE_ADDR + 0x0)
#define     LTSSM_SHIFT                         24
#define     LTSSM_MASK                          0x3f
#define     LTSSM_L0                            0x10
#define     RC_BAR_CONFIG                       0x300
#define VENDOR_ID_REG                           (LMI_BASE_ADDR + 0x44)

/* PCIe core controller registers */
#define CTRL_CORE_BASE_ADDR                     0x18000
#define CTRL_CONFIG_REG                         (CTRL_CORE_BASE_ADDR + 0x0)
#define     CTRL_MODE_SHIFT                     0x0
#define     CTRL_MODE_MASK                      0x1
#define     PCIE_CORE_MODE_DIRECT               0x0
#define     PCIE_CORE_MODE_COMMAND              0x1

/* PCIe Central Interrupts Registers */
#define CENTRAL_INT_BASE_ADDR                   0x1b000
#define HOST_CTRL_INT_STATUS_REG                (CENTRAL_INT_BASE_ADDR + 0x0)
#define HOST_CTRL_INT_MASK_REG                  (CENTRAL_INT_BASE_ADDR + 0x4)
#define     PCIE_IRQ_CMDQ_INT                   BIT(0)
#define     PCIE_IRQ_MSI_STATUS_INT             BIT(1)
#define     PCIE_IRQ_CMD_SENT_DONE              BIT(3)
#define     PCIE_IRQ_DMA_INT                    BIT(4)
#define     PCIE_IRQ_IB_DXFERDONE               BIT(5)
#define     PCIE_IRQ_OB_DXFERDONE               BIT(6)
#define     PCIE_IRQ_OB_RXFERDONE               BIT(7)
#define     PCIE_IRQ_COMPQ_INT                  BIT(12)
#define     PCIE_IRQ_DIR_RD_DDR_DET             BIT(13)
#define     PCIE_IRQ_DIR_WR_DDR_DET             BIT(14)
#define     PCIE_IRQ_CORE_INT                   BIT(16)
#define     PCIE_IRQ_CORE_INT_PIO               BIT(17)
#define     PCIE_IRQ_DPMU_INT                   BIT(18)
#define     PCIE_IRQ_PCIE_MIS_INT               BIT(19)
#define     PCIE_IRQ_MSI_INT1_DET               BIT(20)
#define     PCIE_IRQ_MSI_INT2_DET               BIT(21)
#define     PCIE_IRQ_RC_DBELL_DET               BIT(22)
#define     PCIE_IRQ_EP_STATUS                  BIT(23)
#define     PCIE_IRQ_ALL_MASK                   0xfff0fb
#define     PCIE_IRQ_ENABLE_INTS_MASK           PCIE_IRQ_CORE_INT

/* Transaction types */
#define PCIE_CONFIG_RD_TYPE0                    0x8
#define PCIE_CONFIG_RD_TYPE1                    0x9
#define PCIE_CONFIG_WR_TYPE0                    0xa
#define PCIE_CONFIG_WR_TYPE1                    0xb

#define PIO_RETRY_CNT                   750000 /* 1.5 s */
#define PIO_RETRY_DELAY                 2 /* 2 us*/

#define LINK_WAIT_MAX_RETRIES           10
#define LINK_WAIT_USLEEP_MIN            90000
#define LINK_WAIT_USLEEP_MAX            100000
#define RETRAIN_WAIT_MAX_RETRIES        10
#define RETRAIN_WAIT_USLEEP_US          2000

#define MSI_IRQ_NUM                     32

#define CFG_RD_CRS_VAL                  0xffff0001

struct advk_pcie {
        struct platform_device *pdev;
        void __iomem *base;
        struct {
                phys_addr_t match;
                phys_addr_t remap;
                phys_addr_t mask;
                u32 actions;
        } wins[OB_WIN_COUNT];
        u8 wins_count;
        struct irq_domain *irq_domain;
        struct irq_chip irq_chip;
        raw_spinlock_t irq_lock;
        struct irq_domain *msi_domain;
        struct irq_domain *msi_inner_domain;
        struct irq_chip msi_bottom_irq_chip;
        struct irq_chip msi_irq_chip;
        struct msi_domain_info msi_domain_info;
        DECLARE_BITMAP(msi_used, MSI_IRQ_NUM);
        struct mutex msi_used_lock;
        u16 msi_msg;
        int link_gen;
        struct pci_bridge_emul bridge;
        struct gpio_desc *reset_gpio;
        struct phy *phy;
};

static inline void advk_writel(struct advk_pcie *pcie, u32 val, u64 reg)
{
        writel(val, pcie->base + reg);
}

static inline u32 advk_readl(struct advk_pcie *pcie, u64 reg)
{
        return readl(pcie->base + reg);
}

static inline u16 advk_read16(struct advk_pcie *pcie, u64 reg)
{
        return advk_readl(pcie, (reg & ~0x3)) >> ((reg & 0x3) * 8);
}

static int advk_pcie_link_up(struct advk_pcie *pcie)
{
        u32 val, ltssm_state;

        val = advk_readl(pcie, CFG_REG);
        ltssm_state = (val >> LTSSM_SHIFT) & LTSSM_MASK;
        return ltssm_state >= LTSSM_L0;
}

static int advk_pcie_wait_for_link(struct advk_pcie *pcie)
{
        int retries;

        /* check if the link is up or not */
        for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
                if (advk_pcie_link_up(pcie))
                        return 0;

                usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
        }

        return -ETIMEDOUT;
}

static void advk_pcie_wait_for_retrain(struct advk_pcie *pcie)
{
        size_t retries;

        for (retries = 0; retries < RETRAIN_WAIT_MAX_RETRIES; ++retries) {
                if (!advk_pcie_link_up(pcie))
                        break;
                udelay(RETRAIN_WAIT_USLEEP_US);
        }
}

static void advk_pcie_issue_perst(struct advk_pcie *pcie)
{
        u32 reg;

        if (!pcie->reset_gpio)
                return;

        /*
         * As required by PCI Express spec (PCI Express Base Specification, REV.
         * 4.0 PCI Express, February 19 2014, 6.6.1 Conventional Reset) a delay
         * for at least 100ms after de-asserting PERST# signal is needed before
         * link training is enabled. So ensure that link training is disabled
         * prior de-asserting PERST# signal to fulfill that PCI Express spec
         * requirement.
         */
        reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
        reg &= ~LINK_TRAINING_EN;
        advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);

        /* 10ms delay is needed for some cards */
        dev_info(&pcie->pdev->dev, "issuing PERST via reset GPIO for 10ms\n");
        gpiod_set_value_cansleep(pcie->reset_gpio, 1);
        usleep_range(10000, 11000);
        gpiod_set_value_cansleep(pcie->reset_gpio, 0);
}

static int advk_pcie_train_at_gen(struct advk_pcie *pcie, int gen)
{
        int ret, neg_gen;
        u32 reg;

        /* Setup link speed */
        reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
        reg &= ~PCIE_GEN_SEL_MSK;
        if (gen == 3)
                reg |= SPEED_GEN_3;
        else if (gen == 2)
                reg |= SPEED_GEN_2;
        else
                reg |= SPEED_GEN_1;
        advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);

        /*
         * Enable link training. This is not needed in every call to this
         * function, just once suffices, but it does not break anything either.
         */
        reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
        reg |= LINK_TRAINING_EN;
        advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);

        /*
         * Start link training immediately after enabling it.
         * This solves problems for some buggy cards.
         */
        reg = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + PCI_EXP_LNKCTL);
        reg |= PCI_EXP_LNKCTL_RL;
        advk_writel(pcie, reg, PCIE_CORE_PCIEXP_CAP + PCI_EXP_LNKCTL);

        ret = advk_pcie_wait_for_link(pcie);
        if (ret)
                return ret;

        reg = advk_read16(pcie, PCIE_CORE_PCIEXP_CAP + PCI_EXP_LNKSTA);
        neg_gen = reg & PCI_EXP_LNKSTA_CLS;

        return neg_gen;
}

static void advk_pcie_train_link(struct advk_pcie *pcie)
{
        struct device *dev = &pcie->pdev->dev;
        int neg_gen = -1, gen;

        /*
         * Reset PCIe card via PERST# signal. Some cards are not detected
         * during link training when they are in some non-initial state.
         */
        advk_pcie_issue_perst(pcie);

        /*
         * PERST# signal could have been asserted by pinctrl subsystem before
         * probe() callback has been called or issued explicitly by reset gpio
         * function advk_pcie_issue_perst(), making the endpoint going into
         * fundamental reset. As required by PCI Express spec a delay for at
         * least 100ms after such a reset before link training is needed.
         */
        msleep(PCI_PM_D3COLD_WAIT);

        /*
         * Try link training at link gen specified by device tree property
         * 'max-link-speed'. If this fails, iteratively train at lower gen.
         */
        for (gen = pcie->link_gen; gen > 0; --gen) {
                neg_gen = advk_pcie_train_at_gen(pcie, gen);
                if (neg_gen > 0)
                        break;
        }

        if (neg_gen < 0)
                goto err;

        /*
         * After successful training if negotiated gen is lower than requested,
         * train again on negotiated gen. This solves some stability issues for
         * some buggy gen1 cards.
         */
        if (neg_gen < gen) {
                gen = neg_gen;
                neg_gen = advk_pcie_train_at_gen(pcie, gen);
        }

        if (neg_gen == gen) {
                dev_info(dev, "link up at gen %i\n", gen);
                return;
        }

err:
        dev_err(dev, "link never came up\n");
}

/*
 * Set PCIe address window register which could be used for memory
 * mapping.
 */
static void advk_pcie_set_ob_win(struct advk_pcie *pcie, u8 win_num,
                                 phys_addr_t match, phys_addr_t remap,
                                 phys_addr_t mask, u32 actions)
{
        advk_writel(pcie, OB_WIN_ENABLE |
                          lower_32_bits(match), OB_WIN_MATCH_LS(win_num));
        advk_writel(pcie, upper_32_bits(match), OB_WIN_MATCH_MS(win_num));
        advk_writel(pcie, lower_32_bits(remap), OB_WIN_REMAP_LS(win_num));
        advk_writel(pcie, upper_32_bits(remap), OB_WIN_REMAP_MS(win_num));
        advk_writel(pcie, lower_32_bits(mask), OB_WIN_MASK_LS(win_num));
        advk_writel(pcie, upper_32_bits(mask), OB_WIN_MASK_MS(win_num));
        advk_writel(pcie, actions, OB_WIN_ACTIONS(win_num));
}

static void advk_pcie_disable_ob_win(struct advk_pcie *pcie, u8 win_num)
{
        advk_writel(pcie, 0, OB_WIN_MATCH_LS(win_num));
        advk_writel(pcie, 0, OB_WIN_MATCH_MS(win_num));
        advk_writel(pcie, 0, OB_WIN_REMAP_LS(win_num));
        advk_writel(pcie, 0, OB_WIN_REMAP_MS(win_num));
        advk_writel(pcie, 0, OB_WIN_MASK_LS(win_num));
        advk_writel(pcie, 0, OB_WIN_MASK_MS(win_num));
        advk_writel(pcie, 0, OB_WIN_ACTIONS(win_num));
}

static void advk_pcie_setup_hw(struct advk_pcie *pcie)
{
        u32 reg;
        int i;

        /* Enable TX */
        reg = advk_readl(pcie, PCIE_CORE_REF_CLK_REG);
        reg |= PCIE_CORE_REF_CLK_TX_ENABLE;
        advk_writel(pcie, reg, PCIE_CORE_REF_CLK_REG);

        /* Set to Direct mode */
        reg = advk_readl(pcie, CTRL_CONFIG_REG);
        reg &= ~(CTRL_MODE_MASK << CTRL_MODE_SHIFT);
        reg |= ((PCIE_CORE_MODE_DIRECT & CTRL_MODE_MASK) << CTRL_MODE_SHIFT);
        advk_writel(pcie, reg, CTRL_CONFIG_REG);

        /* Set PCI global control register to RC mode */
        reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
        reg |= (IS_RC_MSK << IS_RC_SHIFT);
        advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);

        /*
         * Replace incorrect PCI vendor id value 0x1b4b by correct value 0x11ab.
         * VENDOR_ID_REG contains vendor id in low 16 bits and subsystem vendor
         * id in high 16 bits. Updating this register changes readback value of
         * read-only vendor id bits in PCIE_CORE_DEV_ID_REG register. Workaround
         * for erratum 4.1: "The value of device and vendor ID is incorrect".
         */
        reg = (PCI_VENDOR_ID_MARVELL << 16) | PCI_VENDOR_ID_MARVELL;
        advk_writel(pcie, reg, VENDOR_ID_REG);

        /* Set Advanced Error Capabilities and Control PF0 register */
        reg = PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX |
                PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX_EN |
                PCIE_CORE_ERR_CAPCTL_ECRC_CHCK |
                PCIE_CORE_ERR_CAPCTL_ECRC_CHCK_RCV;
        advk_writel(pcie, reg, PCIE_CORE_ERR_CAPCTL_REG);

        /* Set PCIe Device Control register */
        reg = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);
        reg &= ~PCI_EXP_DEVCTL_RELAX_EN;
        reg &= ~PCI_EXP_DEVCTL_NOSNOOP_EN;
        reg &= ~PCI_EXP_DEVCTL_READRQ;
        reg |= PCI_EXP_DEVCTL_PAYLOAD; /* Set max payload size */
        reg |= PCI_EXP_DEVCTL_READRQ_512B;
        advk_writel(pcie, reg, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);

        /* Program PCIe Control 2 to disable strict ordering */
        reg = PCIE_CORE_CTRL2_RESERVED |
                PCIE_CORE_CTRL2_TD_ENABLE;
        advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG);

        /* Set lane X1 */
        reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
        reg &= ~LANE_CNT_MSK;
        reg |= LANE_COUNT_1;
        advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);

        /* Enable MSI */
        reg = advk_readl(pcie, PCIE_CORE_CTRL2_REG);
        reg |= PCIE_CORE_CTRL2_MSI_ENABLE;
        advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG);

        /* Clear all interrupts */
        advk_writel(pcie, PCIE_ISR0_ALL_MASK, PCIE_ISR0_REG);
        advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_REG);
        advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_STATUS_REG);

        /* Disable All ISR0/1 Sources */
        reg = PCIE_ISR0_ALL_MASK;
        reg &= ~PCIE_ISR0_MSI_INT_PENDING;
        advk_writel(pcie, reg, PCIE_ISR0_MASK_REG);

        advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_MASK_REG);

        /* Unmask all MSIs */
        advk_writel(pcie, 0, PCIE_MSI_MASK_REG);

        /* Enable summary interrupt for GIC SPI source */
        reg = PCIE_IRQ_ALL_MASK & (~PCIE_IRQ_ENABLE_INTS_MASK);
        advk_writel(pcie, reg, HOST_CTRL_INT_MASK_REG);

        /*
         * Enable AXI address window location generation:
         * When it is enabled, the default outbound window
         * configurations (Default User Field: 0xD0074CFC)
         * are used to transparent address translation for
         * the outbound transactions. Thus, PCIe address
         * windows are not required for transparent memory
         * access when default outbound window configuration
         * is set for memory access.
         */
        reg = advk_readl(pcie, PCIE_CORE_CTRL2_REG);
        reg |= PCIE_CORE_CTRL2_OB_WIN_ENABLE;
        advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG);

        /*
         * Set memory access in Default User Field so it
         * is not required to configure PCIe address for
         * transparent memory access.
         */
        advk_writel(pcie, OB_WIN_TYPE_MEM, OB_WIN_DEFAULT_ACTIONS);

        /*
         * Bypass the address window mapping for PIO:
         * Since PIO access already contains all required
         * info over AXI interface by PIO registers, the
         * address window is not required.
         */
        reg = advk_readl(pcie, PIO_CTRL);
        reg |= PIO_CTRL_ADDR_WIN_DISABLE;
        advk_writel(pcie, reg, PIO_CTRL);

        /*
         * Configure PCIe address windows for non-memory or
         * non-transparent access as by default PCIe uses
         * transparent memory access.
         */
        for (i = 0; i < pcie->wins_count; i++)
                advk_pcie_set_ob_win(pcie, i,
                                     pcie->wins[i].match, pcie->wins[i].remap,
                                     pcie->wins[i].mask, pcie->wins[i].actions);

        /* Disable remaining PCIe outbound windows */
        for (i = pcie->wins_count; i < OB_WIN_COUNT; i++)
                advk_pcie_disable_ob_win(pcie, i);

        advk_pcie_train_link(pcie);

        /*
         * FIXME: The following register update is suspicious. This register is
         * applicable only when the PCI controller is configured for Endpoint
         * mode, not as a Root Complex. But apparently when this code is
         * removed, some cards stop working. This should be investigated and
         * a comment explaining this should be put here.
         */
        reg = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG);
        reg |= PCIE_CORE_CMD_MEM_ACCESS_EN |
                PCIE_CORE_CMD_IO_ACCESS_EN |
                PCIE_CORE_CMD_MEM_IO_REQ_EN;
        advk_writel(pcie, reg, PCIE_CORE_CMD_STATUS_REG);
}

static int advk_pcie_check_pio_status(struct advk_pcie *pcie, bool allow_crs, u32 *val)
{
        struct device *dev = &pcie->pdev->dev;
        u32 reg;
        unsigned int status;
        char *strcomp_status, *str_posted;

        reg = advk_readl(pcie, PIO_STAT);
        status = (reg & PIO_COMPLETION_STATUS_MASK) >>
                PIO_COMPLETION_STATUS_SHIFT;

        /*
         * According to HW spec, the PIO status check sequence as below:
         * 1) even if COMPLETION_STATUS(bit9:7) indicates successful,
         *    it still needs to check Error Status(bit11), only when this bit
         *    indicates no error happen, the operation is successful.
         * 2) value Unsupported Request(1) of COMPLETION_STATUS(bit9:7) only
         *    means a PIO write error, and for PIO read it is successful with
         *    a read value of 0xFFFFFFFF.
         * 3) value Completion Retry Status(CRS) of COMPLETION_STATUS(bit9:7)
         *    only means a PIO write error, and for PIO read it is successful
         *    with a read value of 0xFFFF0001.
         * 4) value Completer Abort (CA) of COMPLETION_STATUS(bit9:7) means
         *    error for both PIO read and PIO write operation.
         * 5) other errors are indicated as 'unknown'.
         */
        switch (status) {
        case PIO_COMPLETION_STATUS_OK:
                if (reg & PIO_ERR_STATUS) {
                        strcomp_status = "COMP_ERR";
                        break;
                }
                /* Get the read result */
                if (val)
                        *val = advk_readl(pcie, PIO_RD_DATA);
                /* No error */
                strcomp_status = NULL;
                break;
        case PIO_COMPLETION_STATUS_UR:
                strcomp_status = "UR";
                break;
        case PIO_COMPLETION_STATUS_CRS:
                if (allow_crs && val) {
                        /* PCIe r4.0, sec 2.3.2, says:
                         * If CRS Software Visibility is enabled:
                         * For a Configuration Read Request that includes both
                         * bytes of the Vendor ID field of a device Function's
                         * Configuration Space Header, the Root Complex must
                         * complete the Request to the host by returning a
                         * read-data value of 0001h for the Vendor ID field and
                         * all '1's for any additional bytes included in the
                         * request.
                         *
                         * So CRS in this case is not an error status.
                         */
                        *val = CFG_RD_CRS_VAL;
                        strcomp_status = NULL;
                        break;
                }
                /* PCIe r4.0, sec 2.3.2, says:
                 * If CRS Software Visibility is not enabled, the Root Complex
                 * must re-issue the Configuration Request as a new Request.
                 * If CRS Software Visibility is enabled: For a Configuration
                 * Write Request or for any other Configuration Read Request,
                 * the Root Complex must re-issue the Configuration Request as
                 * a new Request.
                 * A Root Complex implementation may choose to limit the number
                 * of Configuration Request/CRS Completion Status loops before
                 * determining that something is wrong with the target of the
                 * Request and taking appropriate action, e.g., complete the
                 * Request to the host as a failed transaction.
                 *
                 * To simplify implementation do not re-issue the Configuration
                 * Request and complete the Request as a failed transaction.
                 */
                strcomp_status = "CRS";
                break;
        case PIO_COMPLETION_STATUS_CA:
                strcomp_status = "CA";
                break;
        default:
                strcomp_status = "Unknown";
                break;
        }

        if (!strcomp_status)
                return 0;

        if (reg & PIO_NON_POSTED_REQ)
                str_posted = "Non-posted";
        else
                str_posted = "Posted";

        dev_err(dev, "%s PIO Response Status: %s, %#x @ %#x\n",
                str_posted, strcomp_status, reg, advk_readl(pcie, PIO_ADDR_LS));

        return -EFAULT;
}

static int advk_pcie_wait_pio(struct advk_pcie *pcie)
{
        struct device *dev = &pcie->pdev->dev;
        int i;

        for (i = 0; i < PIO_RETRY_CNT; i++) {
                u32 start, isr;

                start = advk_readl(pcie, PIO_START);
                isr = advk_readl(pcie, PIO_ISR);
                if (!start && isr)
                        return 0;
                udelay(PIO_RETRY_DELAY);
        }

        dev_err(dev, "PIO read/write transfer time out\n");
        return -ETIMEDOUT;
}


static pci_bridge_emul_read_status_t
advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
                                    int reg, u32 *value)
{
        struct advk_pcie *pcie = bridge->data;


        switch (reg) {
        case PCI_EXP_SLTCTL:
                *value = PCI_EXP_SLTSTA_PDS << 16;
                return PCI_BRIDGE_EMUL_HANDLED;

        case PCI_EXP_RTCTL: {
                u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG);
                *value = (val & PCIE_MSG_PM_PME_MASK) ? 0 : PCI_EXP_RTCTL_PMEIE;
                *value |= PCI_EXP_RTCAP_CRSVIS << 16;
                return PCI_BRIDGE_EMUL_HANDLED;
        }

        case PCI_EXP_RTSTA: {
                u32 isr0 = advk_readl(pcie, PCIE_ISR0_REG);
                u32 msglog = advk_readl(pcie, PCIE_MSG_LOG_REG);
                *value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16 | (msglog >> 16);
                return PCI_BRIDGE_EMUL_HANDLED;
        }

        case PCI_EXP_LNKCTL: {
                /* u32 contains both PCI_EXP_LNKCTL and PCI_EXP_LNKSTA */
                u32 val = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + reg) &
                        ~(PCI_EXP_LNKSTA_LT << 16);
                if (!advk_pcie_link_up(pcie))
                        val |= (PCI_EXP_LNKSTA_LT << 16);
                *value = val;
                return PCI_BRIDGE_EMUL_HANDLED;
        }

        case PCI_CAP_LIST_ID:
        case PCI_EXP_DEVCAP:
        case PCI_EXP_DEVCTL:
        case PCI_EXP_LNKCAP:
                *value = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + reg);
                return PCI_BRIDGE_EMUL_HANDLED;
        default:
                return PCI_BRIDGE_EMUL_NOT_HANDLED;
        }

}

static void
advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
                                     int reg, u32 old, u32 new, u32 mask)
{
        struct advk_pcie *pcie = bridge->data;

        switch (reg) {
        case PCI_EXP_DEVCTL:
                advk_writel(pcie, new, PCIE_CORE_PCIEXP_CAP + reg);
                break;

        case PCI_EXP_LNKCTL:
                advk_writel(pcie, new, PCIE_CORE_PCIEXP_CAP + reg);
                if (new & PCI_EXP_LNKCTL_RL)
                        advk_pcie_wait_for_retrain(pcie);
                break;

        case PCI_EXP_RTCTL: {
                /* Only mask/unmask PME interrupt */
                u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) &
                        ~PCIE_MSG_PM_PME_MASK;
                if ((new & PCI_EXP_RTCTL_PMEIE) == 0)
                        val |= PCIE_MSG_PM_PME_MASK;
                advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
                break;
        }

        case PCI_EXP_RTSTA:
                new = (new & PCI_EXP_RTSTA_PME) >> 9;
                advk_writel(pcie, new, PCIE_ISR0_REG);
                break;

        default:
                break;
        }
}

static struct pci_bridge_emul_ops advk_pci_bridge_emul_ops = {
        .read_pcie = advk_pci_bridge_emul_pcie_conf_read,
        .write_pcie = advk_pci_bridge_emul_pcie_conf_write,
};

/*
 * Initialize the configuration space of the PCI-to-PCI bridge
 * associated with the given PCIe interface.
 */
static int advk_sw_pci_bridge_init(struct advk_pcie *pcie)
{
        struct pci_bridge_emul *bridge = &pcie->bridge;
        int ret;

        bridge->conf.vendor =
                cpu_to_le16(advk_readl(pcie, PCIE_CORE_DEV_ID_REG) & 0xffff);
        bridge->conf.device =
                cpu_to_le16(advk_readl(pcie, PCIE_CORE_DEV_ID_REG) >> 16);
        bridge->conf.class_revision =
                cpu_to_le32(advk_readl(pcie, PCIE_CORE_DEV_REV_REG) & 0xff);

        /* Support 32 bits I/O addressing */
        bridge->conf.iobase = PCI_IO_RANGE_TYPE_32;
        bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32;

        /* Support 64 bits memory pref */
        bridge->conf.pref_mem_base = cpu_to_le16(PCI_PREF_RANGE_TYPE_64);
        bridge->conf.pref_mem_limit = cpu_to_le16(PCI_PREF_RANGE_TYPE_64);

        /* Support interrupt A for MSI feature */
        bridge->conf.intpin = PCIE_CORE_INT_A_ASSERT_ENABLE;

        bridge->has_pcie = true;
        bridge->data = pcie;
        bridge->ops = &advk_pci_bridge_emul_ops;

        /* PCIe config space can be initialized after pci_bridge_emul_init() */
        ret = pci_bridge_emul_init(bridge, 0);
        if (ret < 0)
                return ret;

        /* Indicates supports for Completion Retry Status */
        bridge->pcie_conf.rootcap = cpu_to_le16(PCI_EXP_RTCAP_CRSVIS);

        return 0;
}

static bool advk_pcie_valid_device(struct advk_pcie *pcie, struct pci_bus *bus,
                                  int devfn)
{
        if (pci_is_root_bus(bus) && PCI_SLOT(devfn) != 0)
                return false;

        /*
         * If the link goes down after we check for link-up, nothing bad
         * happens but the config access times out.
         */
        if (!pci_is_root_bus(bus) && !advk_pcie_link_up(pcie))
                return false;

        return true;
}

static bool advk_pcie_pio_is_running(struct advk_pcie *pcie)
{
        struct device *dev = &pcie->pdev->dev;

        /*
         * Trying to start a new PIO transfer when previous has not completed
         * cause External Abort on CPU which results in kernel panic:
         *
         *     SError Interrupt on CPU0, code 0xbf000002 -- SError
         *     Kernel panic - not syncing: Asynchronous SError Interrupt
         *
         * Functions advk_pcie_rd_conf() and advk_pcie_wr_conf() are protected
         * by raw_spin_lock_irqsave() at pci_lock_config() level to prevent
         * concurrent calls at the same time. But because PIO transfer may take
         * about 1.5s when link is down or card is disconnected, it means that
         * advk_pcie_wait_pio() does not always have to wait for completion.
         *
         * Some versions of ARM Trusted Firmware handles this External Abort at
         * EL3 level and mask it to prevent kernel panic. Relevant TF-A commit:
         * https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=3c7dcdac5c50
         */
        if (advk_readl(pcie, PIO_START)) {
                dev_err(dev, "Previous PIO read/write transfer is still running\n");
                return true;
        }

        return false;
}

static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
                             int where, int size, u32 *val)
{
        struct advk_pcie *pcie = bus->sysdata;
        bool allow_crs;
        u32 reg;
        int ret;

        if (!advk_pcie_valid_device(pcie, bus, devfn)) {
                *val = 0xffffffff;
                return PCIBIOS_DEVICE_NOT_FOUND;
        }

        if (pci_is_root_bus(bus))
                return pci_bridge_emul_conf_read(&pcie->bridge, where,
                                                 size, val);

        /*
         * Completion Retry Status is possible to return only when reading all
         * 4 bytes from PCI_VENDOR_ID and PCI_DEVICE_ID registers at once and
         * CRSSVE flag on Root Bridge is enabled.
         */
        allow_crs = (where == PCI_VENDOR_ID) && (size == 4) &&
                    (le16_to_cpu(pcie->bridge.pcie_conf.rootctl) &
                     PCI_EXP_RTCTL_CRSSVE);

        if (advk_pcie_pio_is_running(pcie)) {
                /*
                 * If it is possible return Completion Retry Status so caller
                 * tries to issue the request again instead of failing.
                 */
                if (allow_crs) {
                        *val = CFG_RD_CRS_VAL;
                        return PCIBIOS_SUCCESSFUL;
                }
                *val = 0xffffffff;
                return PCIBIOS_SET_FAILED;
        }

        /* Program the control register */
        reg = advk_readl(pcie, PIO_CTRL);
        reg &= ~PIO_CTRL_TYPE_MASK;
        if (pci_is_root_bus(bus->parent))
                reg |= PCIE_CONFIG_RD_TYPE0;
        else
                reg |= PCIE_CONFIG_RD_TYPE1;
        advk_writel(pcie, reg, PIO_CTRL);

        /* Program the address registers */
        reg = ALIGN_DOWN(PCIE_ECAM_OFFSET(bus->number, devfn, where), 4);
        advk_writel(pcie, reg, PIO_ADDR_LS);
        advk_writel(pcie, 0, PIO_ADDR_MS);

        /* Program the data strobe */
        advk_writel(pcie, 0xf, PIO_WR_DATA_STRB);

        /* Clear PIO DONE ISR and start the transfer */
        advk_writel(pcie, 1, PIO_ISR);
        advk_writel(pcie, 1, PIO_START);

        ret = advk_pcie_wait_pio(pcie);
        if (ret < 0) {
                /*
                 * If it is possible return Completion Retry Status so caller
                 * tries to issue the request again instead of failing.
                 */
                if (allow_crs) {
                        *val = CFG_RD_CRS_VAL;
                        return PCIBIOS_SUCCESSFUL;
                }
                *val = 0xffffffff;
                return PCIBIOS_SET_FAILED;
        }

        /* Check PIO status and get the read result */
        ret = advk_pcie_check_pio_status(pcie, allow_crs, val);
        if (ret < 0) {
                *val = 0xffffffff;
                return PCIBIOS_SET_FAILED;
        }

        if (size == 1)
                *val = (*val >> (8 * (where & 3))) & 0xff;
        else if (size == 2)
                *val = (*val >> (8 * (where & 3))) & 0xffff;

        return PCIBIOS_SUCCESSFUL;
}

static int advk_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
                                int where, int size, u32 val)
{
        struct advk_pcie *pcie = bus->sysdata;
        u32 reg;
        u32 data_strobe = 0x0;
        int offset;
        int ret;

        if (!advk_pcie_valid_device(pcie, bus, devfn))
                return PCIBIOS_DEVICE_NOT_FOUND;

        if (pci_is_root_bus(bus))
                return pci_bridge_emul_conf_write(&pcie->bridge, where,
                                                  size, val);

        if (where % size)
                return PCIBIOS_SET_FAILED;

        if (advk_pcie_pio_is_running(pcie))
                return PCIBIOS_SET_FAILED;

        /* Program the control register */
        reg = advk_readl(pcie, PIO_CTRL);

        reg &= ~PIO_CTRL_TYPE_MASK;
        if (pci_is_root_bus(bus->parent))
                reg |= PCIE_CONFIG_WR_TYPE0;
        else
                reg |= PCIE_CONFIG_WR_TYPE1;
        advk_writel(pcie, reg, PIO_CTRL);

        /* Program the address registers */
        reg = ALIGN_DOWN(PCIE_ECAM_OFFSET(bus->number, devfn, where), 4);
        advk_writel(pcie, reg, PIO_ADDR_LS);
        advk_writel(pcie, 0, PIO_ADDR_MS);

        /* Calculate the write strobe */
        offset      = where & 0x3;
        reg         = val << (8 * offset);
        data_strobe = GENMASK(size - 1, 0) << offset;

        /* Program the data register */
        advk_writel(pcie, reg, PIO_WR_DATA);

        /* Program the data strobe */
        advk_writel(pcie, data_strobe, PIO_WR_DATA_STRB);

        /* Clear PIO DONE ISR and start the transfer */
        advk_writel(pcie, 1, PIO_ISR);
        advk_writel(pcie, 1, PIO_START);

        ret = advk_pcie_wait_pio(pcie);
        if (ret < 0)
                return PCIBIOS_SET_FAILED;

        ret = advk_pcie_check_pio_status(pcie, false, NULL);
        if (ret < 0)
                return PCIBIOS_SET_FAILED;

        return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops advk_pcie_ops = {
        .read = advk_pcie_rd_conf,
        .write = advk_pcie_wr_conf,
};

static void advk_msi_irq_compose_msi_msg(struct irq_data *data,
                                         struct msi_msg *msg)
{
        struct advk_pcie *pcie = irq_data_get_irq_chip_data(data);
        phys_addr_t msi_msg = virt_to_phys(&pcie->msi_msg);

        msg->address_lo = lower_32_bits(msi_msg);
        msg->address_hi = upper_32_bits(msi_msg);
        msg->data = data->irq;
}

static int advk_msi_set_affinity(struct irq_data *irq_data,
                                 const struct cpumask *mask, bool force)
{
        return -EINVAL;
}

static int advk_msi_irq_domain_alloc(struct irq_domain *domain,
                                     unsigned int virq,
                                     unsigned int nr_irqs, void *args)
{
        struct advk_pcie *pcie = domain->host_data;
        int hwirq, i;

        mutex_lock(&pcie->msi_used_lock);
        hwirq = bitmap_find_next_zero_area(pcie->msi_used, MSI_IRQ_NUM,
                                           0, nr_irqs, 0);
        if (hwirq >= MSI_IRQ_NUM) {
                mutex_unlock(&pcie->msi_used_lock);
                return -ENOSPC;
        }

        bitmap_set(pcie->msi_used, hwirq, nr_irqs);
        mutex_unlock(&pcie->msi_used_lock);

        for (i = 0; i < nr_irqs; i++)
                irq_domain_set_info(domain, virq + i, hwirq + i,
                                    &pcie->msi_bottom_irq_chip,
                                    domain->host_data, handle_simple_irq,
                                    NULL, NULL);

        return hwirq;
}

static void advk_msi_irq_domain_free(struct irq_domain *domain,
                                     unsigned int virq, unsigned int nr_irqs)
{
        struct irq_data *d = irq_domain_get_irq_data(domain, virq);
        struct advk_pcie *pcie = domain->host_data;

        mutex_lock(&pcie->msi_used_lock);
        bitmap_clear(pcie->msi_used, d->hwirq, nr_irqs);
        mutex_unlock(&pcie->msi_used_lock);
}

static const struct irq_domain_ops advk_msi_domain_ops = {
        .alloc = advk_msi_irq_domain_alloc,
        .free = advk_msi_irq_domain_free,
};

static void advk_pcie_irq_mask(struct irq_data *d)
{
        struct advk_pcie *pcie = d->domain->host_data;
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        unsigned long flags;
        u32 mask;

        raw_spin_lock_irqsave(&pcie->irq_lock, flags);
        mask = advk_readl(pcie, PCIE_ISR1_MASK_REG);
        mask |= PCIE_ISR1_INTX_ASSERT(hwirq);
        advk_writel(pcie, mask, PCIE_ISR1_MASK_REG);
        raw_spin_unlock_irqrestore(&pcie->irq_lock, flags);
}

static void advk_pcie_irq_unmask(struct irq_data *d)
{
        struct advk_pcie *pcie = d->domain->host_data;
        irq_hw_number_t hwirq = irqd_to_hwirq(d);
        unsigned long flags;
        u32 mask;

        raw_spin_lock_irqsave(&pcie->irq_lock, flags);
        mask = advk_readl(pcie, PCIE_ISR1_MASK_REG);
        mask &= ~PCIE_ISR1_INTX_ASSERT(hwirq);
        advk_writel(pcie, mask, PCIE_ISR1_MASK_REG);
        raw_spin_unlock_irqrestore(&pcie->irq_lock, flags);
}

static int advk_pcie_irq_map(struct irq_domain *h,
                             unsigned int virq, irq_hw_number_t hwirq)
{
        struct advk_pcie *pcie = h->host_data;

        advk_pcie_irq_mask(irq_get_irq_data(virq));
        irq_set_status_flags(virq, IRQ_LEVEL);
        irq_set_chip_and_handler(virq, &pcie->irq_chip,
                                 handle_level_irq);
        irq_set_chip_data(virq, pcie);

        return 0;
}

static const struct irq_domain_ops advk_pcie_irq_domain_ops = {
        .map = advk_pcie_irq_map,
        .xlate = irq_domain_xlate_onecell,
};

static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie)
{
        struct device *dev = &pcie->pdev->dev;
        struct device_node *node = dev->of_node;
        struct irq_chip *bottom_ic, *msi_ic;
        struct msi_domain_info *msi_di;
        phys_addr_t msi_msg_phys;

        mutex_init(&pcie->msi_used_lock);

        bottom_ic = &pcie->msi_bottom_irq_chip;

        bottom_ic->name = "MSI";
        bottom_ic->irq_compose_msi_msg = advk_msi_irq_compose_msi_msg;
        bottom_ic->irq_set_affinity = advk_msi_set_affinity;

        msi_ic = &pcie->msi_irq_chip;
        msi_ic->name = "advk-MSI";

        msi_di = &pcie->msi_domain_info;
        msi_di->flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
                MSI_FLAG_MULTI_PCI_MSI;
        msi_di->chip = msi_ic;

        msi_msg_phys = virt_to_phys(&pcie->msi_msg);

        advk_writel(pcie, lower_32_bits(msi_msg_phys),
                    PCIE_MSI_ADDR_LOW_REG);
        advk_writel(pcie, upper_32_bits(msi_msg_phys),
                    PCIE_MSI_ADDR_HIGH_REG);

        pcie->msi_inner_domain =
                irq_domain_add_linear(NULL, MSI_IRQ_NUM,
                                      &advk_msi_domain_ops, pcie);
        if (!pcie->msi_inner_domain)
                return -ENOMEM;

        pcie->msi_domain =
                pci_msi_create_irq_domain(of_node_to_fwnode(node),
                                          msi_di, pcie->msi_inner_domain);
        if (!pcie->msi_domain) {
                irq_domain_remove(pcie->msi_inner_domain);
                return -ENOMEM;
        }

        return 0;
}

static void advk_pcie_remove_msi_irq_domain(struct advk_pcie *pcie)
{
        irq_domain_remove(pcie->msi_domain);
        irq_domain_remove(pcie->msi_inner_domain);
}

static int advk_pcie_init_irq_domain(struct advk_pcie *pcie)
{
        struct device *dev = &pcie->pdev->dev;
        struct device_node *node = dev->of_node;
        struct device_node *pcie_intc_node;
        struct irq_chip *irq_chip;
        int ret = 0;

        raw_spin_lock_init(&pcie->irq_lock);

        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_chip = &pcie->irq_chip;

        irq_chip->name = devm_kasprintf(dev, GFP_KERNEL, "%s-irq",
                                        dev_name(dev));
        if (!irq_chip->name) {
                ret = -ENOMEM;
                goto out_put_node;
        }

        irq_chip->irq_mask = advk_pcie_irq_mask;
        irq_chip->irq_mask_ack = advk_pcie_irq_mask;
        irq_chip->irq_unmask = advk_pcie_irq_unmask;

        pcie->irq_domain =
                irq_domain_add_linear(pcie_intc_node, PCI_NUM_INTX,
                                      &advk_pcie_irq_domain_ops, pcie);
        if (!pcie->irq_domain) {
                dev_err(dev, "Failed to get a INTx IRQ domain\n");
                ret = -ENOMEM;
                goto out_put_node;
        }

out_put_node:
        of_node_put(pcie_intc_node);
        return ret;
}

static void advk_pcie_remove_irq_domain(struct advk_pcie *pcie)
{
        irq_domain_remove(pcie->irq_domain);
}

static void advk_pcie_handle_msi(struct advk_pcie *pcie)
{
        u32 msi_val, msi_mask, msi_status, msi_idx;
        u16 msi_data;

        msi_mask = advk_readl(pcie, PCIE_MSI_MASK_REG);
        msi_val = advk_readl(pcie, PCIE_MSI_STATUS_REG);
        msi_status = msi_val & ~msi_mask;

        for (msi_idx = 0; msi_idx < MSI_IRQ_NUM; msi_idx++) {
                if (!(BIT(msi_idx) & msi_status))
                        continue;

                advk_writel(pcie, BIT(msi_idx), PCIE_MSI_STATUS_REG);
                msi_data = advk_readl(pcie, PCIE_MSI_PAYLOAD_REG) & 0xFF;
                generic_handle_irq(msi_data);
        }

        advk_writel(pcie, PCIE_ISR0_MSI_INT_PENDING,
                    PCIE_ISR0_REG);
}

static void advk_pcie_handle_int(struct advk_pcie *pcie)
{
        u32 isr0_val, isr0_mask, isr0_status;
        u32 isr1_val, isr1_mask, isr1_status;
        int i;

        isr0_val = advk_readl(pcie, PCIE_ISR0_REG);
        isr0_mask = advk_readl(pcie, PCIE_ISR0_MASK_REG);
        isr0_status = isr0_val & ((~isr0_mask) & PCIE_ISR0_ALL_MASK);

        isr1_val = advk_readl(pcie, PCIE_ISR1_REG);
        isr1_mask = advk_readl(pcie, PCIE_ISR1_MASK_REG);
        isr1_status = isr1_val & ((~isr1_mask) & PCIE_ISR1_ALL_MASK);

        if (!isr0_status && !isr1_status) {
                advk_writel(pcie, isr0_val, PCIE_ISR0_REG);
                advk_writel(pcie, isr1_val, PCIE_ISR1_REG);
                return;
        }

        /* Process MSI interrupts */
        if (isr0_status & PCIE_ISR0_MSI_INT_PENDING)
                advk_pcie_handle_msi(pcie);

        /* Process legacy interrupts */
        for (i = 0; i < PCI_NUM_INTX; i++) {
                if (!(isr1_status & PCIE_ISR1_INTX_ASSERT(i)))
                        continue;

                advk_writel(pcie, PCIE_ISR1_INTX_ASSERT(i),
                            PCIE_ISR1_REG);

                generic_handle_domain_irq(pcie->irq_domain, i);
        }
}

static irqreturn_t advk_pcie_irq_handler(int irq, void *arg)
{
        struct advk_pcie *pcie = arg;
        u32 status;

        status = advk_readl(pcie, HOST_CTRL_INT_STATUS_REG);
        if (!(status & PCIE_IRQ_CORE_INT))
                return IRQ_NONE;

        advk_pcie_handle_int(pcie);

        /* Clear interrupt */
        advk_writel(pcie, PCIE_IRQ_CORE_INT, HOST_CTRL_INT_STATUS_REG);

        return IRQ_HANDLED;
}

static void __maybe_unused advk_pcie_disable_phy(struct advk_pcie *pcie)
{
        phy_power_off(pcie->phy);
        phy_exit(pcie->phy);
}

static int advk_pcie_enable_phy(struct advk_pcie *pcie)
{
        int ret;

        if (!pcie->phy)
                return 0;

        ret = phy_init(pcie->phy);
        if (ret)
                return ret;

        ret = phy_set_mode(pcie->phy, PHY_MODE_PCIE);
        if (ret) {
                phy_exit(pcie->phy);
                return ret;
        }

        ret = phy_power_on(pcie->phy);
        if (ret == -EOPNOTSUPP) {
                dev_warn(&pcie->pdev->dev, "PHY unsupported by firmware\n");
        } else if (ret) {
                phy_exit(pcie->phy);
                return ret;
        }

        return 0;
}

static int advk_pcie_setup_phy(struct advk_pcie *pcie)
{
        struct device *dev = &pcie->pdev->dev;
        struct device_node *node = dev->of_node;
        int ret = 0;

        pcie->phy = devm_of_phy_get(dev, node, NULL);
        if (IS_ERR(pcie->phy) && (PTR_ERR(pcie->phy) == -EPROBE_DEFER))
                return PTR_ERR(pcie->phy);

        /* Old bindings miss the PHY handle */
        if (IS_ERR(pcie->phy)) {
                dev_warn(dev, "PHY unavailable (%ld)\n", PTR_ERR(pcie->phy));
                pcie->phy = NULL;
                return 0;
        }

        ret = advk_pcie_enable_phy(pcie);
        if (ret)
                dev_err(dev, "Failed to initialize PHY (%d)\n", ret);

        return ret;
}

static int advk_pcie_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct advk_pcie *pcie;
        struct pci_host_bridge *bridge;
        struct resource_entry *entry;
        int ret, irq;

        bridge = devm_pci_alloc_host_bridge(dev, sizeof(struct advk_pcie));
        if (!bridge)
                return -ENOMEM;

        pcie = pci_host_bridge_priv(bridge);
        pcie->pdev = pdev;
        platform_set_drvdata(pdev, pcie);

        resource_list_for_each_entry(entry, &bridge->windows) {
                resource_size_t start = entry->res->start;
                resource_size_t size = resource_size(entry->res);
                unsigned long type = resource_type(entry->res);
                u64 win_size;

                /*
                 * Aardvark hardware allows to configure also PCIe window
                 * for config type 0 and type 1 mapping, but driver uses
                 * only PIO for issuing configuration transfers which does
                 * not use PCIe window configuration.
                 */
                if (type != IORESOURCE_MEM && type != IORESOURCE_MEM_64 &&
                    type != IORESOURCE_IO)
                        continue;

                /*
                 * Skip transparent memory resources. Default outbound access
                 * configuration is set to transparent memory access so it
                 * does not need window configuration.
                 */
                if ((type == IORESOURCE_MEM || type == IORESOURCE_MEM_64) &&
                    entry->offset == 0)
                        continue;

                /*
                 * The n-th PCIe window is configured by tuple (match, remap, mask)
                 * and an access to address A uses this window if A matches the
                 * match with given mask.
                 * So every PCIe window size must be a power of two and every start
                 * address must be aligned to window size. Minimal size is 64 KiB
                 * because lower 16 bits of mask must be zero. Remapped address
                 * may have set only bits from the mask.
                 */
                while (pcie->wins_count < OB_WIN_COUNT && size > 0) {
                        /* Calculate the largest aligned window size */
                        win_size = (1ULL << (fls64(size)-1)) |
                                   (start ? (1ULL << __ffs64(start)) : 0);
                        win_size = 1ULL << __ffs64(win_size);
                        if (win_size < 0x10000)
                                break;

                        dev_dbg(dev,
                                "Configuring PCIe window %d: [0x%llx-0x%llx] as %lu\n",
                                pcie->wins_count, (unsigned long long)start,
                                (unsigned long long)start + win_size, type);

                        if (type == IORESOURCE_IO) {
                                pcie->wins[pcie->wins_count].actions = OB_WIN_TYPE_IO;
                                pcie->wins[pcie->wins_count].match = pci_pio_to_address(start);
                        } else {
                                pcie->wins[pcie->wins_count].actions = OB_WIN_TYPE_MEM;
                                pcie->wins[pcie->wins_count].match = start;
                        }
                        pcie->wins[pcie->wins_count].remap = start - entry->offset;
                        pcie->wins[pcie->wins_count].mask = ~(win_size - 1);

                        if (pcie->wins[pcie->wins_count].remap & (win_size - 1))
                                break;

                        start += win_size;
                        size -= win_size;
                        pcie->wins_count++;
                }

                if (size > 0) {
                        dev_err(&pcie->pdev->dev,
                                "Invalid PCIe region [0x%llx-0x%llx]\n",
                                (unsigned long long)entry->res->start,
                                (unsigned long long)entry->res->end + 1);
                        return -EINVAL;
                }
        }

        pcie->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(pcie->base))
                return PTR_ERR(pcie->base);

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

        ret = devm_request_irq(dev, irq, advk_pcie_irq_handler,
                               IRQF_SHARED | IRQF_NO_THREAD, "advk-pcie",
                               pcie);
        if (ret) {
                dev_err(dev, "Failed to register interrupt\n");
                return ret;
        }

        pcie->reset_gpio = devm_gpiod_get_from_of_node(dev, dev->of_node,
                                                       "reset-gpios", 0,
                                                       GPIOD_OUT_LOW,
                                                       "pcie1-reset");
        ret = PTR_ERR_OR_ZERO(pcie->reset_gpio);
        if (ret) {
                if (ret == -ENOENT) {
                        pcie->reset_gpio = NULL;
                } else {
                        if (ret != -EPROBE_DEFER)
                                dev_err(dev, "Failed to get reset-gpio: %i\n",
                                        ret);
                        return ret;
                }
        }

        ret = of_pci_get_max_link_speed(dev->of_node);
        if (ret <= 0 || ret > 3)
                pcie->link_gen = 3;
        else
                pcie->link_gen = ret;

        ret = advk_pcie_setup_phy(pcie);
        if (ret)
                return ret;

        advk_pcie_setup_hw(pcie);

        ret = advk_sw_pci_bridge_init(pcie);
        if (ret) {
                dev_err(dev, "Failed to register emulated root PCI bridge\n");
                return ret;
        }

        ret = advk_pcie_init_irq_domain(pcie);
        if (ret) {
                dev_err(dev, "Failed to initialize irq\n");
                return ret;
        }

        ret = advk_pcie_init_msi_irq_domain(pcie);
        if (ret) {
                dev_err(dev, "Failed to initialize irq\n");
                advk_pcie_remove_irq_domain(pcie);
                return ret;
        }

        bridge->sysdata = pcie;
        bridge->ops = &advk_pcie_ops;

        ret = pci_host_probe(bridge);
        if (ret < 0) {
                advk_pcie_remove_msi_irq_domain(pcie);
                advk_pcie_remove_irq_domain(pcie);
                return ret;
        }

        return 0;
}

static int advk_pcie_remove(struct platform_device *pdev)
{
        struct advk_pcie *pcie = platform_get_drvdata(pdev);
        struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
        int i;

        pci_lock_rescan_remove();
        pci_stop_root_bus(bridge->bus);
        pci_remove_root_bus(bridge->bus);
        pci_unlock_rescan_remove();

        advk_pcie_remove_msi_irq_domain(pcie);
        advk_pcie_remove_irq_domain(pcie);

        /* Disable outbound address windows mapping */
        for (i = 0; i < OB_WIN_COUNT; i++)
                advk_pcie_disable_ob_win(pcie, i);

        return 0;
}

static const struct of_device_id advk_pcie_of_match_table[] = {
        { .compatible = "marvell,armada-3700-pcie", },
        {},
};
MODULE_DEVICE_TABLE(of, advk_pcie_of_match_table);

static struct platform_driver advk_pcie_driver = {
        .driver = {
                .name = "advk-pcie",
                .of_match_table = advk_pcie_of_match_table,
        },
        .probe = advk_pcie_probe,
        .remove = advk_pcie_remove,
};
module_platform_driver(advk_pcie_driver);

MODULE_DESCRIPTION("Aardvark PCIe controller");
MODULE_LICENSE("GPL v2");