// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2015, Bin Meng <bmeng.cn@gmail.com>
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <irq.h>
#include <log.h>
#include <malloc.h>
#include <asm/global_data.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/pci.h>
#include <asm/pirq_routing.h>
#include <asm/tables.h>

DECLARE_GLOBAL_DATA_PTR;

/**
 * pirq_reg_to_linkno() - Convert a PIRQ routing register offset to link number
 *
 * @priv:       IRQ router driver's priv data
 * @reg:        PIRQ routing register offset from the base address
 * @return:     PIRQ link number (0 for PIRQA, 1 for PIRQB, etc)
 */
static inline int pirq_reg_to_linkno(struct irq_router *priv, int reg)
{
        int linkno = 0;

        if (priv->has_regmap) {
                struct pirq_regmap *map = priv->regmap;
                int i;

                for (i = 0; i < priv->link_num; i++) {
                        if (reg - priv->link_base == map->offset) {
                                linkno = map->link;
                                break;
                        }
                        map++;
                }
        } else {
                linkno = reg - priv->link_base;
        }

        return linkno;
}

/**
 * pirq_linkno_to_reg() - Convert a PIRQ link number to routing register offset
 *
 * @priv:       IRQ router driver's priv data
 * @linkno:     PIRQ link number (0 for PIRQA, 1 for PIRQB, etc)
 * @return:     PIRQ routing register offset from the base address
 */
static inline int pirq_linkno_to_reg(struct irq_router *priv, int linkno)
{
        int reg = 0;

        if (priv->has_regmap) {
                struct pirq_regmap *map = priv->regmap;
                int i;

                for (i = 0; i < priv->link_num; i++) {
                        if (linkno == map->link) {
                                reg = map->offset + priv->link_base;
                                break;
                        }
                        map++;
                }
        } else {
                reg = linkno + priv->link_base;
        }

        return reg;
}

bool pirq_check_irq_routed(struct udevice *dev, int link, u8 irq)
{
        struct irq_router *priv = dev_get_priv(dev);
        u8 pirq;

        if (priv->config == PIRQ_VIA_PCI)
                dm_pci_read_config8(dev->parent,
                                    pirq_linkno_to_reg(priv, link), &pirq);
        else
                pirq = readb((uintptr_t)priv->ibase +
                             pirq_linkno_to_reg(priv, link));

        pirq &= 0xf;

        /* IRQ# 0/1/2/8/13 are reserved */
        if (pirq < 3 || pirq == 8 || pirq == 13)
                return false;

        return pirq == irq ? true : false;
}

int pirq_translate_link(struct udevice *dev, int link)
{
        struct irq_router *priv = dev_get_priv(dev);

        return pirq_reg_to_linkno(priv, link);
}

void pirq_assign_irq(struct udevice *dev, int link, u8 irq)
{
        struct irq_router *priv = dev_get_priv(dev);

        /* IRQ# 0/1/2/8/13 are reserved */
        if (irq < 3 || irq == 8 || irq == 13)
                return;

        if (priv->config == PIRQ_VIA_PCI)
                dm_pci_write_config8(dev->parent,
                                     pirq_linkno_to_reg(priv, link), irq);
        else
                writeb(irq, (uintptr_t)priv->ibase +
                       pirq_linkno_to_reg(priv, link));
}

static struct irq_info *check_dup_entry(struct irq_info *slot_base,
                                        int entry_num, int bus, int device)
{
        struct irq_info *slot = slot_base;
        int i;

        for (i = 0; i < entry_num; i++) {
                if (slot->bus == bus && slot->devfn == (device << 3))
                        break;
                slot++;
        }

        return (i == entry_num) ? NULL : slot;
}

static inline void fill_irq_info(struct irq_router *priv, struct irq_info *slot,
                                 int bus, int device, int pin, int pirq)
{
        slot->bus = bus;
        slot->devfn = (device << 3) | 0;
        slot->irq[pin - 1].link = pirq_linkno_to_reg(priv, pirq);
        slot->irq[pin - 1].bitmap = priv->irq_mask;
}

static int create_pirq_routing_table(struct udevice *dev)
{
        struct irq_router *priv = dev_get_priv(dev);
        const void *blob = gd->fdt_blob;
        int node;
        int len, count;
        const u32 *cell;
        struct pirq_regmap *map;
        struct irq_routing_table *rt;
        struct irq_info *slot, *slot_base;
        int irq_entries = 0;
        int i;
        int ret;

        node = dev_of_offset(dev);

        /* extract the bdf from fdt_pci_addr */
        priv->bdf = dm_pci_get_bdf(dev->parent);

        ret = fdt_stringlist_search(blob, node, "intel,pirq-config", "pci");
        if (!ret) {
                priv->config = PIRQ_VIA_PCI;
        } else {
                ret = fdt_stringlist_search(blob, node, "intel,pirq-config",
                                            "ibase");
                if (!ret)
                        priv->config = PIRQ_VIA_IBASE;
                else
                        return -EINVAL;
        }

        cell = fdt_getprop(blob, node, "intel,pirq-link", &len);
        if (!cell || len != 8)
                return -EINVAL;
        priv->link_base = fdt_addr_to_cpu(cell[0]);
        priv->link_num = fdt_addr_to_cpu(cell[1]);
        if (priv->link_num > CONFIG_MAX_PIRQ_LINKS) {
                debug("Limiting supported PIRQ link number from %d to %d\n",
                      priv->link_num, CONFIG_MAX_PIRQ_LINKS);
                priv->link_num = CONFIG_MAX_PIRQ_LINKS;
        }

        cell = fdt_getprop(blob, node, "intel,pirq-regmap", &len);
        if (cell) {
                if (len % sizeof(struct pirq_regmap))
                        return -EINVAL;

                count = len / sizeof(struct pirq_regmap);
                if (count < priv->link_num) {
                        printf("Number of pirq-regmap entires is wrong\n");
                        return -EINVAL;
                }

                count = priv->link_num;
                priv->regmap = calloc(count, sizeof(struct pirq_regmap));
                if (!priv->regmap)
                        return -ENOMEM;

                priv->has_regmap = true;
                map = priv->regmap;
                for (i = 0; i < count; i++) {
                        map->link = fdt_addr_to_cpu(cell[0]);
                        map->offset = fdt_addr_to_cpu(cell[1]);

                        cell += sizeof(struct pirq_regmap) / sizeof(u32);
                        map++;
                }
        }

        priv->irq_mask = fdtdec_get_int(blob, node,
                                        "intel,pirq-mask", PIRQ_BITMAP);

        if (IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE)) {
                /* Reserve IRQ9 for SCI */
                priv->irq_mask &= ~(1 << 9);
        }

        if (priv->config == PIRQ_VIA_IBASE) {
                int ibase_off;

                ibase_off = fdtdec_get_int(blob, node, "intel,ibase-offset", 0);
                if (!ibase_off)
                        return -EINVAL;

                /*
                 * Here we assume that the IBASE register has already been
                 * properly configured by U-Boot before.
                 *
                 * By 'valid' we mean:
                 *   1) a valid memory space carved within system memory space
                 *      assigned to IBASE register block.
                 *   2) memory range decoding is enabled.
                 * Hence we don't do any santify test here.
                 */
                dm_pci_read_config32(dev->parent, ibase_off, &priv->ibase);
                priv->ibase &= ~0xf;
        }

        priv->actl_8bit = fdtdec_get_bool(blob, node, "intel,actl-8bit");
        priv->actl_addr = fdtdec_get_int(blob, node, "intel,actl-addr", 0);

        cell = fdt_getprop(blob, node, "intel,pirq-routing", &len);
        if (!cell || len % sizeof(struct pirq_routing))
                return -EINVAL;
        count = len / sizeof(struct pirq_routing);

        rt = calloc(1, sizeof(struct irq_routing_table));
        if (!rt)
                return -ENOMEM;

        /* Populate the PIRQ table fields */
        rt->signature = PIRQ_SIGNATURE;
        rt->version = PIRQ_VERSION;
        rt->rtr_bus = PCI_BUS(priv->bdf);
        rt->rtr_devfn = (PCI_DEV(priv->bdf) << 3) | PCI_FUNC(priv->bdf);
        rt->rtr_vendor = PCI_VENDOR_ID_INTEL;
        rt->rtr_device = PCI_DEVICE_ID_INTEL_ICH7_31;

        slot_base = rt->slots;

        /* Now fill in the irq_info entries in the PIRQ table */
        for (i = 0; i < count;
             i++, cell += sizeof(struct pirq_routing) / sizeof(u32)) {
                struct pirq_routing pr;

                pr.bdf = fdt_addr_to_cpu(cell[0]);
                pr.pin = fdt_addr_to_cpu(cell[1]);
                pr.pirq = fdt_addr_to_cpu(cell[2]);

                debug("irq_info %d: b.d.f %x.%x.%x INT%c PIRQ%c\n",
                      i, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
                      PCI_FUNC(pr.bdf), 'A' + pr.pin - 1,
                      'A' + pr.pirq);

                slot = check_dup_entry(slot_base, irq_entries,
                                       PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));
                if (slot) {
                        debug("found entry for bus %d device %d, ",
                              PCI_BUS(pr.bdf), PCI_DEV(pr.bdf));

                        if (slot->irq[pr.pin - 1].link) {
                                debug("skipping\n");

                                /*
                                 * Sanity test on the routed PIRQ pin
                                 *
                                 * If they don't match, show a warning to tell
                                 * there might be something wrong with the PIRQ
                                 * routing information in the device tree.
                                 */
                                if (slot->irq[pr.pin - 1].link !=
                                    pirq_linkno_to_reg(priv, pr.pirq))
                                        debug("WARNING: Inconsistent PIRQ routing information\n");
                                continue;
                        }
                } else {
                        slot = slot_base + irq_entries++;
                }
                debug("writing INT%c\n", 'A' + pr.pin - 1);
                fill_irq_info(priv, slot, PCI_BUS(pr.bdf), PCI_DEV(pr.bdf),
                              pr.pin, pr.pirq);
        }

        rt->size = irq_entries * sizeof(struct irq_info) + 32;

        /* Fix up the table checksum */
        rt->checksum = table_compute_checksum(rt, rt->size);

        gd->arch.pirq_routing_table = rt;

        return 0;
}

static void irq_enable_sci(struct udevice *dev)
{
        struct irq_router *priv = dev_get_priv(dev);

        if (priv->actl_8bit) {
                /* Bit7 must be turned on to enable ACPI */
                dm_pci_write_config8(dev->parent, priv->actl_addr, 0x80);
        } else {
                /* Write 0 to enable SCI on IRQ9 */
                if (priv->config == PIRQ_VIA_PCI)
                        dm_pci_write_config32(dev->parent, priv->actl_addr, 0);
                else
                        writel(0, (uintptr_t)priv->ibase + priv->actl_addr);
        }
}

int irq_router_probe(struct udevice *dev)
{
        int ret;

        ret = create_pirq_routing_table(dev);
        if (ret) {
                debug("Failed to create pirq routing table\n");
                return ret;
        }
        /* Route PIRQ */
        pirq_route_irqs(dev, gd->arch.pirq_routing_table->slots,
                        get_irq_slot_count(gd->arch.pirq_routing_table));

        if (IS_ENABLED(CONFIG_GENERATE_ACPI_TABLE))
                irq_enable_sci(dev);

        return 0;
}

static const struct udevice_id irq_router_ids[] = {
        { .compatible = "intel,irq-router", .data = X86_IRQT_BASE },
        { }
};

U_BOOT_DRIVER(irq_router_drv) = {
        .name           = "intel_irq",
        .id             = UCLASS_IRQ,
        .of_match       = irq_router_ids,
        .probe          = irq_router_probe,
        .priv_auto      = sizeof(struct irq_router),
};