Linux 4.19.133

[linux/fpc-iii.git] / drivers / pci / controller / pcie-xilinx-nwl.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * PCIe host controller driver for NWL PCIe Bridge
 * Based on pcie-xilinx.c, pci-tegra.c
 *
 * (C) Copyright 2014 - 2015, Xilinx, Inc.
 */

#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/of_irq.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/irqchip/chained_irq.h>

#include "../pci.h"

/* Bridge core config registers */
#define BRCFG_PCIE_RX0                  0x00000000
#define BRCFG_INTERRUPT                 0x00000010
#define BRCFG_PCIE_RX_MSG_FILTER        0x00000020

/* Egress - Bridge translation registers */
#define E_BREG_CAPABILITIES             0x00000200
#define E_BREG_CONTROL                  0x00000208
#define E_BREG_BASE_LO                  0x00000210
#define E_BREG_BASE_HI                  0x00000214
#define E_ECAM_CAPABILITIES             0x00000220
#define E_ECAM_CONTROL                  0x00000228
#define E_ECAM_BASE_LO                  0x00000230
#define E_ECAM_BASE_HI                  0x00000234

/* Ingress - address translations */
#define I_MSII_CAPABILITIES             0x00000300
#define I_MSII_CONTROL                  0x00000308
#define I_MSII_BASE_LO                  0x00000310
#define I_MSII_BASE_HI                  0x00000314

#define I_ISUB_CONTROL                  0x000003E8
#define SET_ISUB_CONTROL                BIT(0)
/* Rxed msg fifo  - Interrupt status registers */
#define MSGF_MISC_STATUS                0x00000400
#define MSGF_MISC_MASK                  0x00000404
#define MSGF_LEG_STATUS                 0x00000420
#define MSGF_LEG_MASK                   0x00000424
#define MSGF_MSI_STATUS_LO              0x00000440
#define MSGF_MSI_STATUS_HI              0x00000444
#define MSGF_MSI_MASK_LO                0x00000448
#define MSGF_MSI_MASK_HI                0x0000044C

/* Msg filter mask bits */
#define CFG_ENABLE_PM_MSG_FWD           BIT(1)
#define CFG_ENABLE_INT_MSG_FWD          BIT(2)
#define CFG_ENABLE_ERR_MSG_FWD          BIT(3)
#define CFG_ENABLE_MSG_FILTER_MASK      (CFG_ENABLE_PM_MSG_FWD | \
                                        CFG_ENABLE_INT_MSG_FWD | \
                                        CFG_ENABLE_ERR_MSG_FWD)

/* Misc interrupt status mask bits */
#define MSGF_MISC_SR_RXMSG_AVAIL        BIT(0)
#define MSGF_MISC_SR_RXMSG_OVER         BIT(1)
#define MSGF_MISC_SR_SLAVE_ERR          BIT(4)
#define MSGF_MISC_SR_MASTER_ERR         BIT(5)
#define MSGF_MISC_SR_I_ADDR_ERR         BIT(6)
#define MSGF_MISC_SR_E_ADDR_ERR         BIT(7)
#define MSGF_MISC_SR_FATAL_AER          BIT(16)
#define MSGF_MISC_SR_NON_FATAL_AER      BIT(17)
#define MSGF_MISC_SR_CORR_AER           BIT(18)
#define MSGF_MISC_SR_UR_DETECT          BIT(20)
#define MSGF_MISC_SR_NON_FATAL_DEV      BIT(22)
#define MSGF_MISC_SR_FATAL_DEV          BIT(23)
#define MSGF_MISC_SR_LINK_DOWN          BIT(24)
#define MSGF_MSIC_SR_LINK_AUTO_BWIDTH   BIT(25)
#define MSGF_MSIC_SR_LINK_BWIDTH        BIT(26)

#define MSGF_MISC_SR_MASKALL            (MSGF_MISC_SR_RXMSG_AVAIL | \
                                        MSGF_MISC_SR_RXMSG_OVER | \
                                        MSGF_MISC_SR_SLAVE_ERR | \
                                        MSGF_MISC_SR_MASTER_ERR | \
                                        MSGF_MISC_SR_I_ADDR_ERR | \
                                        MSGF_MISC_SR_E_ADDR_ERR | \
                                        MSGF_MISC_SR_FATAL_AER | \
                                        MSGF_MISC_SR_NON_FATAL_AER | \
                                        MSGF_MISC_SR_CORR_AER | \
                                        MSGF_MISC_SR_UR_DETECT | \
                                        MSGF_MISC_SR_NON_FATAL_DEV | \
                                        MSGF_MISC_SR_FATAL_DEV | \
                                        MSGF_MISC_SR_LINK_DOWN | \
                                        MSGF_MSIC_SR_LINK_AUTO_BWIDTH | \
                                        MSGF_MSIC_SR_LINK_BWIDTH)

/* Legacy interrupt status mask bits */
#define MSGF_LEG_SR_INTA                BIT(0)
#define MSGF_LEG_SR_INTB                BIT(1)
#define MSGF_LEG_SR_INTC                BIT(2)
#define MSGF_LEG_SR_INTD                BIT(3)
#define MSGF_LEG_SR_MASKALL             (MSGF_LEG_SR_INTA | MSGF_LEG_SR_INTB | \
                                        MSGF_LEG_SR_INTC | MSGF_LEG_SR_INTD)

/* MSI interrupt status mask bits */
#define MSGF_MSI_SR_LO_MASK             GENMASK(31, 0)
#define MSGF_MSI_SR_HI_MASK             GENMASK(31, 0)

#define MSII_PRESENT                    BIT(0)
#define MSII_ENABLE                     BIT(0)
#define MSII_STATUS_ENABLE              BIT(15)

/* Bridge config interrupt mask */
#define BRCFG_INTERRUPT_MASK            BIT(0)
#define BREG_PRESENT                    BIT(0)
#define BREG_ENABLE                     BIT(0)
#define BREG_ENABLE_FORCE               BIT(1)

/* E_ECAM status mask bits */
#define E_ECAM_PRESENT                  BIT(0)
#define E_ECAM_CR_ENABLE                BIT(0)
#define E_ECAM_SIZE_LOC                 GENMASK(20, 16)
#define E_ECAM_SIZE_SHIFT               16
#define ECAM_BUS_LOC_SHIFT              20
#define ECAM_DEV_LOC_SHIFT              12
#define NWL_ECAM_VALUE_DEFAULT          12

#define CFG_DMA_REG_BAR                 GENMASK(2, 0)

#define INT_PCI_MSI_NR                  (2 * 32)

/* Readin the PS_LINKUP */
#define PS_LINKUP_OFFSET                0x00000238
#define PCIE_PHY_LINKUP_BIT             BIT(0)
#define PHY_RDY_LINKUP_BIT              BIT(1)

/* Parameters for the waiting for link up routine */
#define LINK_WAIT_MAX_RETRIES          10
#define LINK_WAIT_USLEEP_MIN           90000
#define LINK_WAIT_USLEEP_MAX           100000

struct nwl_msi {                        /* MSI information */
        struct irq_domain *msi_domain;
        unsigned long *bitmap;
        struct irq_domain *dev_domain;
        struct mutex lock;              /* protect bitmap variable */
        int irq_msi0;
        int irq_msi1;
};

struct nwl_pcie {
        struct device *dev;
        void __iomem *breg_base;
        void __iomem *pcireg_base;
        void __iomem *ecam_base;
        phys_addr_t phys_breg_base;     /* Physical Bridge Register Base */
        phys_addr_t phys_pcie_reg_base; /* Physical PCIe Controller Base */
        phys_addr_t phys_ecam_base;     /* Physical Configuration Base */
        u32 breg_size;
        u32 pcie_reg_size;
        u32 ecam_size;
        int irq_intx;
        int irq_misc;
        u32 ecam_value;
        u8 last_busno;
        u8 root_busno;
        struct nwl_msi msi;
        struct irq_domain *legacy_irq_domain;
        raw_spinlock_t leg_mask_lock;
};

static inline u32 nwl_bridge_readl(struct nwl_pcie *pcie, u32 off)
{
        return readl(pcie->breg_base + off);
}

static inline void nwl_bridge_writel(struct nwl_pcie *pcie, u32 val, u32 off)
{
        writel(val, pcie->breg_base + off);
}

static bool nwl_pcie_link_up(struct nwl_pcie *pcie)
{
        if (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) & PCIE_PHY_LINKUP_BIT)
                return true;
        return false;
}

static bool nwl_phy_link_up(struct nwl_pcie *pcie)
{
        if (readl(pcie->pcireg_base + PS_LINKUP_OFFSET) & PHY_RDY_LINKUP_BIT)
                return true;
        return false;
}

static int nwl_wait_for_link(struct nwl_pcie *pcie)
{
        struct device *dev = pcie->dev;
        int retries;

        /* check if the link is up or not */
        for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
                if (nwl_phy_link_up(pcie))
                        return 0;
                usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
        }

        dev_err(dev, "PHY link never came up\n");
        return -ETIMEDOUT;
}

static bool nwl_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
{
        struct nwl_pcie *pcie = bus->sysdata;

        /* Check link before accessing downstream ports */
        if (bus->number != pcie->root_busno) {
                if (!nwl_pcie_link_up(pcie))
                        return false;
        }

        /* Only one device down on each root port */
        if (bus->number == pcie->root_busno && devfn > 0)
                return false;

        return true;
}

/**
 * nwl_pcie_map_bus - Get configuration base
 *
 * @bus: Bus structure of current bus
 * @devfn: Device/function
 * @where: Offset from base
 *
 * Return: Base address of the configuration space needed to be
 *         accessed.
 */
static void __iomem *nwl_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
                                      int where)
{
        struct nwl_pcie *pcie = bus->sysdata;
        int relbus;

        if (!nwl_pcie_valid_device(bus, devfn))
                return NULL;

        relbus = (bus->number << ECAM_BUS_LOC_SHIFT) |
                        (devfn << ECAM_DEV_LOC_SHIFT);

        return pcie->ecam_base + relbus + where;
}

/* PCIe operations */
static struct pci_ops nwl_pcie_ops = {
        .map_bus = nwl_pcie_map_bus,
        .read  = pci_generic_config_read,
        .write = pci_generic_config_write,
};

static irqreturn_t nwl_pcie_misc_handler(int irq, void *data)
{
        struct nwl_pcie *pcie = data;
        struct device *dev = pcie->dev;
        u32 misc_stat;

        /* Checking for misc interrupts */
        misc_stat = nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
                                     MSGF_MISC_SR_MASKALL;
        if (!misc_stat)
                return IRQ_NONE;

        if (misc_stat & MSGF_MISC_SR_RXMSG_OVER)
                dev_err(dev, "Received Message FIFO Overflow\n");

        if (misc_stat & MSGF_MISC_SR_SLAVE_ERR)
                dev_err(dev, "Slave error\n");

        if (misc_stat & MSGF_MISC_SR_MASTER_ERR)
                dev_err(dev, "Master error\n");

        if (misc_stat & MSGF_MISC_SR_I_ADDR_ERR)
                dev_err(dev, "In Misc Ingress address translation error\n");

        if (misc_stat & MSGF_MISC_SR_E_ADDR_ERR)
                dev_err(dev, "In Misc Egress address translation error\n");

        if (misc_stat & MSGF_MISC_SR_FATAL_AER)
                dev_err(dev, "Fatal Error in AER Capability\n");

        if (misc_stat & MSGF_MISC_SR_NON_FATAL_AER)
                dev_err(dev, "Non-Fatal Error in AER Capability\n");

        if (misc_stat & MSGF_MISC_SR_CORR_AER)
                dev_err(dev, "Correctable Error in AER Capability\n");

        if (misc_stat & MSGF_MISC_SR_UR_DETECT)
                dev_err(dev, "Unsupported request Detected\n");

        if (misc_stat & MSGF_MISC_SR_NON_FATAL_DEV)
                dev_err(dev, "Non-Fatal Error Detected\n");

        if (misc_stat & MSGF_MISC_SR_FATAL_DEV)
                dev_err(dev, "Fatal Error Detected\n");

        if (misc_stat & MSGF_MSIC_SR_LINK_AUTO_BWIDTH)
                dev_info(dev, "Link Autonomous Bandwidth Management Status bit set\n");

        if (misc_stat & MSGF_MSIC_SR_LINK_BWIDTH)
                dev_info(dev, "Link Bandwidth Management Status bit set\n");

        /* Clear misc interrupt status */
        nwl_bridge_writel(pcie, misc_stat, MSGF_MISC_STATUS);

        return IRQ_HANDLED;
}

static void nwl_pcie_leg_handler(struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct nwl_pcie *pcie;
        unsigned long status;
        u32 bit;
        u32 virq;

        chained_irq_enter(chip, desc);
        pcie = irq_desc_get_handler_data(desc);

        while ((status = nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
                                MSGF_LEG_SR_MASKALL) != 0) {
                for_each_set_bit(bit, &status, PCI_NUM_INTX) {
                        virq = irq_find_mapping(pcie->legacy_irq_domain, bit);
                        if (virq)
                                generic_handle_irq(virq);
                }
        }

        chained_irq_exit(chip, desc);
}

static void nwl_pcie_handle_msi_irq(struct nwl_pcie *pcie, u32 status_reg)
{
        struct nwl_msi *msi;
        unsigned long status;
        u32 bit;
        u32 virq;

        msi = &pcie->msi;

        while ((status = nwl_bridge_readl(pcie, status_reg)) != 0) {
                for_each_set_bit(bit, &status, 32) {
                        nwl_bridge_writel(pcie, 1 << bit, status_reg);
                        virq = irq_find_mapping(msi->dev_domain, bit);
                        if (virq)
                                generic_handle_irq(virq);
                }
        }
}

static void nwl_pcie_msi_handler_high(struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct nwl_pcie *pcie = irq_desc_get_handler_data(desc);

        chained_irq_enter(chip, desc);
        nwl_pcie_handle_msi_irq(pcie, MSGF_MSI_STATUS_HI);
        chained_irq_exit(chip, desc);
}

static void nwl_pcie_msi_handler_low(struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        struct nwl_pcie *pcie = irq_desc_get_handler_data(desc);

        chained_irq_enter(chip, desc);
        nwl_pcie_handle_msi_irq(pcie, MSGF_MSI_STATUS_LO);
        chained_irq_exit(chip, desc);
}

static void nwl_mask_leg_irq(struct irq_data *data)
{
        struct irq_desc *desc = irq_to_desc(data->irq);
        struct nwl_pcie *pcie;
        unsigned long flags;
        u32 mask;
        u32 val;

        pcie = irq_desc_get_chip_data(desc);
        mask = 1 << (data->hwirq - 1);
        raw_spin_lock_irqsave(&pcie->leg_mask_lock, flags);
        val = nwl_bridge_readl(pcie, MSGF_LEG_MASK);
        nwl_bridge_writel(pcie, (val & (~mask)), MSGF_LEG_MASK);
        raw_spin_unlock_irqrestore(&pcie->leg_mask_lock, flags);
}

static void nwl_unmask_leg_irq(struct irq_data *data)
{
        struct irq_desc *desc = irq_to_desc(data->irq);
        struct nwl_pcie *pcie;
        unsigned long flags;
        u32 mask;
        u32 val;

        pcie = irq_desc_get_chip_data(desc);
        mask = 1 << (data->hwirq - 1);
        raw_spin_lock_irqsave(&pcie->leg_mask_lock, flags);
        val = nwl_bridge_readl(pcie, MSGF_LEG_MASK);
        nwl_bridge_writel(pcie, (val | mask), MSGF_LEG_MASK);
        raw_spin_unlock_irqrestore(&pcie->leg_mask_lock, flags);
}

static struct irq_chip nwl_leg_irq_chip = {
        .name = "nwl_pcie:legacy",
        .irq_enable = nwl_unmask_leg_irq,
        .irq_disable = nwl_mask_leg_irq,
        .irq_mask = nwl_mask_leg_irq,
        .irq_unmask = nwl_unmask_leg_irq,
};

static int nwl_legacy_map(struct irq_domain *domain, unsigned int irq,
                          irq_hw_number_t hwirq)
{
        irq_set_chip_and_handler(irq, &nwl_leg_irq_chip, handle_level_irq);
        irq_set_chip_data(irq, domain->host_data);
        irq_set_status_flags(irq, IRQ_LEVEL);

        return 0;
}

static const struct irq_domain_ops legacy_domain_ops = {
        .map = nwl_legacy_map,
        .xlate = pci_irqd_intx_xlate,
};

#ifdef CONFIG_PCI_MSI
static struct irq_chip nwl_msi_irq_chip = {
        .name = "nwl_pcie:msi",
        .irq_enable = unmask_msi_irq,
        .irq_disable = mask_msi_irq,
        .irq_mask = mask_msi_irq,
        .irq_unmask = unmask_msi_irq,

};

static struct msi_domain_info nwl_msi_domain_info = {
        .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
                  MSI_FLAG_MULTI_PCI_MSI),
        .chip = &nwl_msi_irq_chip,
};
#endif

static void nwl_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
{
        struct nwl_pcie *pcie = irq_data_get_irq_chip_data(data);
        phys_addr_t msi_addr = pcie->phys_pcie_reg_base;

        msg->address_lo = lower_32_bits(msi_addr);
        msg->address_hi = upper_32_bits(msi_addr);
        msg->data = data->hwirq;
}

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

static struct irq_chip nwl_irq_chip = {
        .name = "Xilinx MSI",
        .irq_compose_msi_msg = nwl_compose_msi_msg,
        .irq_set_affinity = nwl_msi_set_affinity,
};

static int nwl_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
                                unsigned int nr_irqs, void *args)
{
        struct nwl_pcie *pcie = domain->host_data;
        struct nwl_msi *msi = &pcie->msi;
        int bit;
        int i;

        mutex_lock(&msi->lock);
        bit = bitmap_find_free_region(msi->bitmap, INT_PCI_MSI_NR,
                                      get_count_order(nr_irqs));
        if (bit < 0) {
                mutex_unlock(&msi->lock);
                return -ENOSPC;
        }

        for (i = 0; i < nr_irqs; i++) {
                irq_domain_set_info(domain, virq + i, bit + i, &nwl_irq_chip,
                                domain->host_data, handle_simple_irq,
                                NULL, NULL);
        }
        mutex_unlock(&msi->lock);
        return 0;
}

static void nwl_irq_domain_free(struct irq_domain *domain, unsigned int virq,
                                        unsigned int nr_irqs)
{
        struct irq_data *data = irq_domain_get_irq_data(domain, virq);
        struct nwl_pcie *pcie = irq_data_get_irq_chip_data(data);
        struct nwl_msi *msi = &pcie->msi;

        mutex_lock(&msi->lock);
        bitmap_release_region(msi->bitmap, data->hwirq,
                              get_count_order(nr_irqs));
        mutex_unlock(&msi->lock);
}

static const struct irq_domain_ops dev_msi_domain_ops = {
        .alloc  = nwl_irq_domain_alloc,
        .free   = nwl_irq_domain_free,
};

static int nwl_pcie_init_msi_irq_domain(struct nwl_pcie *pcie)
{
#ifdef CONFIG_PCI_MSI
        struct device *dev = pcie->dev;
        struct fwnode_handle *fwnode = of_node_to_fwnode(dev->of_node);
        struct nwl_msi *msi = &pcie->msi;

        msi->dev_domain = irq_domain_add_linear(NULL, INT_PCI_MSI_NR,
                                                &dev_msi_domain_ops, pcie);
        if (!msi->dev_domain) {
                dev_err(dev, "failed to create dev IRQ domain\n");
                return -ENOMEM;
        }
        msi->msi_domain = pci_msi_create_irq_domain(fwnode,
                                                    &nwl_msi_domain_info,
                                                    msi->dev_domain);
        if (!msi->msi_domain) {
                dev_err(dev, "failed to create msi IRQ domain\n");
                irq_domain_remove(msi->dev_domain);
                return -ENOMEM;
        }
#endif
        return 0;
}

static int nwl_pcie_init_irq_domain(struct nwl_pcie *pcie)
{
        struct device *dev = pcie->dev;
        struct device_node *node = dev->of_node;
        struct device_node *legacy_intc_node;

        legacy_intc_node = of_get_next_child(node, NULL);
        if (!legacy_intc_node) {
                dev_err(dev, "No legacy intc node found\n");
                return -EINVAL;
        }

        pcie->legacy_irq_domain = irq_domain_add_linear(legacy_intc_node,
                                                        PCI_NUM_INTX,
                                                        &legacy_domain_ops,
                                                        pcie);
        of_node_put(legacy_intc_node);
        if (!pcie->legacy_irq_domain) {
                dev_err(dev, "failed to create IRQ domain\n");
                return -ENOMEM;
        }

        raw_spin_lock_init(&pcie->leg_mask_lock);
        nwl_pcie_init_msi_irq_domain(pcie);
        return 0;
}

static int nwl_pcie_enable_msi(struct nwl_pcie *pcie)
{
        struct device *dev = pcie->dev;
        struct platform_device *pdev = to_platform_device(dev);
        struct nwl_msi *msi = &pcie->msi;
        unsigned long base;
        int ret;
        int size = BITS_TO_LONGS(INT_PCI_MSI_NR) * sizeof(long);

        mutex_init(&msi->lock);

        msi->bitmap = kzalloc(size, GFP_KERNEL);
        if (!msi->bitmap)
                return -ENOMEM;

        /* Get msi_1 IRQ number */
        msi->irq_msi1 = platform_get_irq_byname(pdev, "msi1");
        if (msi->irq_msi1 < 0) {
                dev_err(dev, "failed to get IRQ#%d\n", msi->irq_msi1);
                ret = -EINVAL;
                goto err;
        }

        irq_set_chained_handler_and_data(msi->irq_msi1,
                                         nwl_pcie_msi_handler_high, pcie);

        /* Get msi_0 IRQ number */
        msi->irq_msi0 = platform_get_irq_byname(pdev, "msi0");
        if (msi->irq_msi0 < 0) {
                dev_err(dev, "failed to get IRQ#%d\n", msi->irq_msi0);
                ret = -EINVAL;
                goto err;
        }

        irq_set_chained_handler_and_data(msi->irq_msi0,
                                         nwl_pcie_msi_handler_low, pcie);

        /* Check for msii_present bit */
        ret = nwl_bridge_readl(pcie, I_MSII_CAPABILITIES) & MSII_PRESENT;
        if (!ret) {
                dev_err(dev, "MSI not present\n");
                ret = -EIO;
                goto err;
        }

        /* Enable MSII */
        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, I_MSII_CONTROL) |
                          MSII_ENABLE, I_MSII_CONTROL);

        /* Enable MSII status */
        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, I_MSII_CONTROL) |
                          MSII_STATUS_ENABLE, I_MSII_CONTROL);

        /* setup AFI/FPCI range */
        base = pcie->phys_pcie_reg_base;
        nwl_bridge_writel(pcie, lower_32_bits(base), I_MSII_BASE_LO);
        nwl_bridge_writel(pcie, upper_32_bits(base), I_MSII_BASE_HI);

        /*
         * For high range MSI interrupts: disable, clear any pending,
         * and enable
         */
        nwl_bridge_writel(pcie, 0, MSGF_MSI_MASK_HI);

        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie,  MSGF_MSI_STATUS_HI) &
                          MSGF_MSI_SR_HI_MASK, MSGF_MSI_STATUS_HI);

        nwl_bridge_writel(pcie, MSGF_MSI_SR_HI_MASK, MSGF_MSI_MASK_HI);

        /*
         * For low range MSI interrupts: disable, clear any pending,
         * and enable
         */
        nwl_bridge_writel(pcie, 0, MSGF_MSI_MASK_LO);

        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MSI_STATUS_LO) &
                          MSGF_MSI_SR_LO_MASK, MSGF_MSI_STATUS_LO);

        nwl_bridge_writel(pcie, MSGF_MSI_SR_LO_MASK, MSGF_MSI_MASK_LO);

        return 0;
err:
        kfree(msi->bitmap);
        msi->bitmap = NULL;
        return ret;
}

static int nwl_pcie_bridge_init(struct nwl_pcie *pcie)
{
        struct device *dev = pcie->dev;
        struct platform_device *pdev = to_platform_device(dev);
        u32 breg_val, ecam_val, first_busno = 0;
        int err;

        breg_val = nwl_bridge_readl(pcie, E_BREG_CAPABILITIES) & BREG_PRESENT;
        if (!breg_val) {
                dev_err(dev, "BREG is not present\n");
                return breg_val;
        }

        /* Write bridge_off to breg base */
        nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_breg_base),
                          E_BREG_BASE_LO);
        nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_breg_base),
                          E_BREG_BASE_HI);

        /* Enable BREG */
        nwl_bridge_writel(pcie, ~BREG_ENABLE_FORCE & BREG_ENABLE,
                          E_BREG_CONTROL);

        /* Disable DMA channel registers */
        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_PCIE_RX0) |
                          CFG_DMA_REG_BAR, BRCFG_PCIE_RX0);

        /* Enable Ingress subtractive decode translation */
        nwl_bridge_writel(pcie, SET_ISUB_CONTROL, I_ISUB_CONTROL);

        /* Enable msg filtering details */
        nwl_bridge_writel(pcie, CFG_ENABLE_MSG_FILTER_MASK,
                          BRCFG_PCIE_RX_MSG_FILTER);

        err = nwl_wait_for_link(pcie);
        if (err)
                return err;

        ecam_val = nwl_bridge_readl(pcie, E_ECAM_CAPABILITIES) & E_ECAM_PRESENT;
        if (!ecam_val) {
                dev_err(dev, "ECAM is not present\n");
                return ecam_val;
        }

        /* Enable ECAM */
        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
                          E_ECAM_CR_ENABLE, E_ECAM_CONTROL);

        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, E_ECAM_CONTROL) |
                          (pcie->ecam_value << E_ECAM_SIZE_SHIFT),
                          E_ECAM_CONTROL);

        nwl_bridge_writel(pcie, lower_32_bits(pcie->phys_ecam_base),
                          E_ECAM_BASE_LO);
        nwl_bridge_writel(pcie, upper_32_bits(pcie->phys_ecam_base),
                          E_ECAM_BASE_HI);

        /* Get bus range */
        ecam_val = nwl_bridge_readl(pcie, E_ECAM_CONTROL);
        pcie->last_busno = (ecam_val & E_ECAM_SIZE_LOC) >> E_ECAM_SIZE_SHIFT;
        /* Write primary, secondary and subordinate bus numbers */
        ecam_val = first_busno;
        ecam_val |= (first_busno + 1) << 8;
        ecam_val |= (pcie->last_busno << E_ECAM_SIZE_SHIFT);
        writel(ecam_val, (pcie->ecam_base + PCI_PRIMARY_BUS));

        if (nwl_pcie_link_up(pcie))
                dev_info(dev, "Link is UP\n");
        else
                dev_info(dev, "Link is DOWN\n");

        /* Get misc IRQ number */
        pcie->irq_misc = platform_get_irq_byname(pdev, "misc");
        if (pcie->irq_misc < 0) {
                dev_err(dev, "failed to get misc IRQ %d\n",
                        pcie->irq_misc);
                return -EINVAL;
        }

        err = devm_request_irq(dev, pcie->irq_misc,
                               nwl_pcie_misc_handler, IRQF_SHARED,
                               "nwl_pcie:misc", pcie);
        if (err) {
                dev_err(dev, "fail to register misc IRQ#%d\n",
                        pcie->irq_misc);
                return err;
        }

        /* Disable all misc interrupts */
        nwl_bridge_writel(pcie, (u32)~MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);

        /* Clear pending misc interrupts */
        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_MISC_STATUS) &
                          MSGF_MISC_SR_MASKALL, MSGF_MISC_STATUS);

        /* Enable all misc interrupts */
        nwl_bridge_writel(pcie, MSGF_MISC_SR_MASKALL, MSGF_MISC_MASK);


        /* Disable all legacy interrupts */
        nwl_bridge_writel(pcie, (u32)~MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);

        /* Clear pending legacy interrupts */
        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, MSGF_LEG_STATUS) &
                          MSGF_LEG_SR_MASKALL, MSGF_LEG_STATUS);

        /* Enable all legacy interrupts */
        nwl_bridge_writel(pcie, MSGF_LEG_SR_MASKALL, MSGF_LEG_MASK);

        /* Enable the bridge config interrupt */
        nwl_bridge_writel(pcie, nwl_bridge_readl(pcie, BRCFG_INTERRUPT) |
                          BRCFG_INTERRUPT_MASK, BRCFG_INTERRUPT);

        return 0;
}

static int nwl_pcie_parse_dt(struct nwl_pcie *pcie,
                             struct platform_device *pdev)
{
        struct device *dev = pcie->dev;
        struct device_node *node = dev->of_node;
        struct resource *res;
        const char *type;

        /* Check for device type */
        type = of_get_property(node, "device_type", NULL);
        if (!type || strcmp(type, "pci")) {
                dev_err(dev, "invalid \"device_type\" %s\n", type);
                return -EINVAL;
        }

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "breg");
        pcie->breg_base = devm_ioremap_resource(dev, res);
        if (IS_ERR(pcie->breg_base))
                return PTR_ERR(pcie->breg_base);
        pcie->phys_breg_base = res->start;

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcireg");
        pcie->pcireg_base = devm_ioremap_resource(dev, res);
        if (IS_ERR(pcie->pcireg_base))
                return PTR_ERR(pcie->pcireg_base);
        pcie->phys_pcie_reg_base = res->start;

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cfg");
        pcie->ecam_base = devm_pci_remap_cfg_resource(dev, res);
        if (IS_ERR(pcie->ecam_base))
                return PTR_ERR(pcie->ecam_base);
        pcie->phys_ecam_base = res->start;

        /* Get intx IRQ number */
        pcie->irq_intx = platform_get_irq_byname(pdev, "intx");
        if (pcie->irq_intx < 0) {
                dev_err(dev, "failed to get intx IRQ %d\n", pcie->irq_intx);
                return pcie->irq_intx;
        }

        irq_set_chained_handler_and_data(pcie->irq_intx,
                                         nwl_pcie_leg_handler, pcie);

        return 0;
}

static const struct of_device_id nwl_pcie_of_match[] = {
        { .compatible = "xlnx,nwl-pcie-2.11", },
        {}
};

static int nwl_pcie_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct nwl_pcie *pcie;
        struct pci_bus *bus;
        struct pci_bus *child;
        struct pci_host_bridge *bridge;
        int err;
        resource_size_t iobase = 0;
        LIST_HEAD(res);

        bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
        if (!bridge)
                return -ENODEV;

        pcie = pci_host_bridge_priv(bridge);

        pcie->dev = dev;
        pcie->ecam_value = NWL_ECAM_VALUE_DEFAULT;

        err = nwl_pcie_parse_dt(pcie, pdev);
        if (err) {
                dev_err(dev, "Parsing DT failed\n");
                return err;
        }

        err = nwl_pcie_bridge_init(pcie);
        if (err) {
                dev_err(dev, "HW Initialization failed\n");
                return err;
        }

        err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, &res,
                                                    &iobase);
        if (err) {
                dev_err(dev, "Getting bridge resources failed\n");
                return err;
        }

        err = devm_request_pci_bus_resources(dev, &res);
        if (err)
                goto error;

        err = nwl_pcie_init_irq_domain(pcie);
        if (err) {
                dev_err(dev, "Failed creating IRQ Domain\n");
                goto error;
        }

        list_splice_init(&res, &bridge->windows);
        bridge->dev.parent = dev;
        bridge->sysdata = pcie;
        bridge->busnr = pcie->root_busno;
        bridge->ops = &nwl_pcie_ops;
        bridge->map_irq = of_irq_parse_and_map_pci;
        bridge->swizzle_irq = pci_common_swizzle;

        if (IS_ENABLED(CONFIG_PCI_MSI)) {
                err = nwl_pcie_enable_msi(pcie);
                if (err < 0) {
                        dev_err(dev, "failed to enable MSI support: %d\n", err);
                        goto error;
                }
        }

        err = pci_scan_root_bus_bridge(bridge);
        if (err)
                goto error;

        bus = bridge->bus;

        pci_assign_unassigned_bus_resources(bus);
        list_for_each_entry(child, &bus->children, node)
                pcie_bus_configure_settings(child);
        pci_bus_add_devices(bus);
        return 0;

error:
        pci_free_resource_list(&res);
        return err;
}

static struct platform_driver nwl_pcie_driver = {
        .driver = {
                .name = "nwl-pcie",
                .suppress_bind_attrs = true,
                .of_match_table = nwl_pcie_of_match,
        },
        .probe = nwl_pcie_probe,
};
builtin_platform_driver(nwl_pcie_driver);