// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org),
 *                    IBM Corp.
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/irq.h>

#include <asm/sections.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/iommu.h>
#include <asm/ppc-pci.h>
#include <asm/isa-bridge.h>

#include "maple.h"

#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif

static struct pci_controller *u3_agp, *u3_ht, *u4_pcie;

static int __init fixup_one_level_bus_range(struct device_node *node, int higher)
{
        for (; node != 0;node = node->sibling) {
                const int *bus_range;
                const unsigned int *class_code;
                int len;

                /* For PCI<->PCI bridges or CardBus bridges, we go down */
                class_code = of_get_property(node, "class-code", NULL);
                if (!class_code || ((*class_code >> 8) != PCI_CLASS_BRIDGE_PCI &&
                        (*class_code >> 8) != PCI_CLASS_BRIDGE_CARDBUS))
                        continue;
                bus_range = of_get_property(node, "bus-range", &len);
                if (bus_range != NULL && len > 2 * sizeof(int)) {
                        if (bus_range[1] > higher)
                                higher = bus_range[1];
                }
                higher = fixup_one_level_bus_range(node->child, higher);
        }
        return higher;
}

/* This routine fixes the "bus-range" property of all bridges in the
 * system since they tend to have their "last" member wrong on macs
 *
 * Note that the bus numbers manipulated here are OF bus numbers, they
 * are not Linux bus numbers.
 */
static void __init fixup_bus_range(struct device_node *bridge)
{
        int *bus_range;
        struct property *prop;
        int len;

        /* Lookup the "bus-range" property for the hose */
        prop = of_find_property(bridge, "bus-range", &len);
        if (prop == NULL  || prop->value == NULL || len < 2 * sizeof(int)) {
                printk(KERN_WARNING "Can't get bus-range for %pOF\n",
                               bridge);
                return;
        }
        bus_range = prop->value;
        bus_range[1] = fixup_one_level_bus_range(bridge->child, bus_range[1]);
}


static unsigned long u3_agp_cfa0(u8 devfn, u8 off)
{
        return (1 << (unsigned long)PCI_SLOT(devfn)) |
                ((unsigned long)PCI_FUNC(devfn) << 8) |
                ((unsigned long)off & 0xFCUL);
}

static unsigned long u3_agp_cfa1(u8 bus, u8 devfn, u8 off)
{
        return ((unsigned long)bus << 16) |
                ((unsigned long)devfn << 8) |
                ((unsigned long)off & 0xFCUL) |
                1UL;
}

static volatile void __iomem *u3_agp_cfg_access(struct pci_controller* hose,
                                       u8 bus, u8 dev_fn, u8 offset)
{
        unsigned int caddr;

        if (bus == hose->first_busno) {
                if (dev_fn < (11 << 3))
                        return NULL;
                caddr = u3_agp_cfa0(dev_fn, offset);
        } else
                caddr = u3_agp_cfa1(bus, dev_fn, offset);

        /* Uninorth will return garbage if we don't read back the value ! */
        do {
                out_le32(hose->cfg_addr, caddr);
        } while (in_le32(hose->cfg_addr) != caddr);

        offset &= 0x07;
        return hose->cfg_data + offset;
}

static int u3_agp_read_config(struct pci_bus *bus, unsigned int devfn,
                              int offset, int len, u32 *val)
{
        struct pci_controller *hose;
        volatile void __iomem *addr;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return PCIBIOS_DEVICE_NOT_FOUND;

        addr = u3_agp_cfg_access(hose, bus->number, devfn, offset);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;
        /*
         * Note: the caller has already checked that offset is
         * suitably aligned and that len is 1, 2 or 4.
         */
        switch (len) {
        case 1:
                *val = in_8(addr);
                break;
        case 2:
                *val = in_le16(addr);
                break;
        default:
                *val = in_le32(addr);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static int u3_agp_write_config(struct pci_bus *bus, unsigned int devfn,
                               int offset, int len, u32 val)
{
        struct pci_controller *hose;
        volatile void __iomem *addr;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return PCIBIOS_DEVICE_NOT_FOUND;

        addr = u3_agp_cfg_access(hose, bus->number, devfn, offset);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;
        /*
         * Note: the caller has already checked that offset is
         * suitably aligned and that len is 1, 2 or 4.
         */
        switch (len) {
        case 1:
                out_8(addr, val);
                break;
        case 2:
                out_le16(addr, val);
                break;
        default:
                out_le32(addr, val);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops u3_agp_pci_ops =
{
        .read = u3_agp_read_config,
        .write = u3_agp_write_config,
};

static unsigned long u3_ht_cfa0(u8 devfn, u8 off)
{
        return (devfn << 8) | off;
}

static unsigned long u3_ht_cfa1(u8 bus, u8 devfn, u8 off)
{
        return u3_ht_cfa0(devfn, off) + (bus << 16) + 0x01000000UL;
}

static volatile void __iomem *u3_ht_cfg_access(struct pci_controller* hose,
                                      u8 bus, u8 devfn, u8 offset)
{
        if (bus == hose->first_busno) {
                if (PCI_SLOT(devfn) == 0)
                        return NULL;
                return hose->cfg_data + u3_ht_cfa0(devfn, offset);
        } else
                return hose->cfg_data + u3_ht_cfa1(bus, devfn, offset);
}

static int u3_ht_root_read_config(struct pci_controller *hose, u8 offset,
                                  int len, u32 *val)
{
        volatile void __iomem *addr;

        addr = hose->cfg_addr;
        addr += ((offset & ~3) << 2) + (4 - len - (offset & 3));

        switch (len) {
        case 1:
                *val = in_8(addr);
                break;
        case 2:
                *val = in_be16(addr);
                break;
        default:
                *val = in_be32(addr);
                break;
        }

        return PCIBIOS_SUCCESSFUL;
}

static int u3_ht_root_write_config(struct pci_controller *hose, u8 offset,
                                  int len, u32 val)
{
        volatile void __iomem *addr;

        addr = hose->cfg_addr + ((offset & ~3) << 2) + (4 - len - (offset & 3));

        if (offset >= PCI_BASE_ADDRESS_0 && offset < PCI_CAPABILITY_LIST)
                return PCIBIOS_SUCCESSFUL;

        switch (len) {
        case 1:
                out_8(addr, val);
                break;
        case 2:
                out_be16(addr, val);
                break;
        default:
                out_be32(addr, val);
                break;
        }

        return PCIBIOS_SUCCESSFUL;
}

static int u3_ht_read_config(struct pci_bus *bus, unsigned int devfn,
                             int offset, int len, u32 *val)
{
        struct pci_controller *hose;
        volatile void __iomem *addr;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return PCIBIOS_DEVICE_NOT_FOUND;

        if (bus->number == hose->first_busno && devfn == PCI_DEVFN(0, 0))
                return u3_ht_root_read_config(hose, offset, len, val);

        if (offset > 0xff)
                return PCIBIOS_BAD_REGISTER_NUMBER;

        addr = u3_ht_cfg_access(hose, bus->number, devfn, offset);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;

        /*
         * Note: the caller has already checked that offset is
         * suitably aligned and that len is 1, 2 or 4.
         */
        switch (len) {
        case 1:
                *val = in_8(addr);
                break;
        case 2:
                *val = in_le16(addr);
                break;
        default:
                *val = in_le32(addr);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static int u3_ht_write_config(struct pci_bus *bus, unsigned int devfn,
                              int offset, int len, u32 val)
{
        struct pci_controller *hose;
        volatile void __iomem *addr;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return PCIBIOS_DEVICE_NOT_FOUND;

        if (bus->number == hose->first_busno && devfn == PCI_DEVFN(0, 0))
                return u3_ht_root_write_config(hose, offset, len, val);

        if (offset > 0xff)
                return PCIBIOS_BAD_REGISTER_NUMBER;

        addr = u3_ht_cfg_access(hose, bus->number, devfn, offset);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;
        /*
         * Note: the caller has already checked that offset is
         * suitably aligned and that len is 1, 2 or 4.
         */
        switch (len) {
        case 1:
                out_8(addr, val);
                break;
        case 2:
                out_le16(addr, val);
                break;
        default:
                out_le32(addr, val);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops u3_ht_pci_ops =
{
        .read = u3_ht_read_config,
        .write = u3_ht_write_config,
};

static unsigned int u4_pcie_cfa0(unsigned int devfn, unsigned int off)
{
        return (1 << PCI_SLOT(devfn))   |
               (PCI_FUNC(devfn) << 8)   |
               ((off >> 8) << 28)       |
               (off & 0xfcu);
}

static unsigned int u4_pcie_cfa1(unsigned int bus, unsigned int devfn,
                                 unsigned int off)
{
        return (bus << 16)              |
               (devfn << 8)             |
               ((off >> 8) << 28)       |
               (off & 0xfcu)            | 1u;
}

static volatile void __iomem *u4_pcie_cfg_access(struct pci_controller* hose,
                                        u8 bus, u8 dev_fn, int offset)
{
        unsigned int caddr;

        if (bus == hose->first_busno)
                caddr = u4_pcie_cfa0(dev_fn, offset);
        else
                caddr = u4_pcie_cfa1(bus, dev_fn, offset);

        /* Uninorth will return garbage if we don't read back the value ! */
        do {
                out_le32(hose->cfg_addr, caddr);
        } while (in_le32(hose->cfg_addr) != caddr);

        offset &= 0x03;
        return hose->cfg_data + offset;
}

static int u4_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
                               int offset, int len, u32 *val)
{
        struct pci_controller *hose;
        volatile void __iomem *addr;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return PCIBIOS_DEVICE_NOT_FOUND;
        if (offset >= 0x1000)
                return  PCIBIOS_BAD_REGISTER_NUMBER;
        addr = u4_pcie_cfg_access(hose, bus->number, devfn, offset);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;
        /*
         * Note: the caller has already checked that offset is
         * suitably aligned and that len is 1, 2 or 4.
         */
        switch (len) {
        case 1:
                *val = in_8(addr);
                break;
        case 2:
                *val = in_le16(addr);
                break;
        default:
                *val = in_le32(addr);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}
static int u4_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
                                int offset, int len, u32 val)
{
        struct pci_controller *hose;
        volatile void __iomem *addr;

        hose = pci_bus_to_host(bus);
        if (hose == NULL)
                return PCIBIOS_DEVICE_NOT_FOUND;
        if (offset >= 0x1000)
                return  PCIBIOS_BAD_REGISTER_NUMBER;
        addr = u4_pcie_cfg_access(hose, bus->number, devfn, offset);
        if (!addr)
                return PCIBIOS_DEVICE_NOT_FOUND;
        /*
         * Note: the caller has already checked that offset is
         * suitably aligned and that len is 1, 2 or 4.
         */
        switch (len) {
        case 1:
                out_8(addr, val);
                break;
        case 2:
                out_le16(addr, val);
                break;
        default:
                out_le32(addr, val);
                break;
        }
        return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops u4_pcie_pci_ops =
{
        .read = u4_pcie_read_config,
        .write = u4_pcie_write_config,
};

static void __init setup_u3_agp(struct pci_controller* hose)
{
        /* On G5, we move AGP up to high bus number so we don't need
         * to reassign bus numbers for HT. If we ever have P2P bridges
         * on AGP, we'll have to move pci_assign_all_buses to the
         * pci_controller structure so we enable it for AGP and not for
         * HT childs.
         * We hard code the address because of the different size of
         * the reg address cell, we shall fix that by killing struct
         * reg_property and using some accessor functions instead
         */
        hose->first_busno = 0xf0;
        hose->last_busno = 0xff;
        hose->ops = &u3_agp_pci_ops;
        hose->cfg_addr = ioremap(0xf0000000 + 0x800000, 0x1000);
        hose->cfg_data = ioremap(0xf0000000 + 0xc00000, 0x1000);

        u3_agp = hose;
}

static void __init setup_u4_pcie(struct pci_controller* hose)
{
        /* We currently only implement the "non-atomic" config space, to
         * be optimised later.
         */
        hose->ops = &u4_pcie_pci_ops;
        hose->cfg_addr = ioremap(0xf0000000 + 0x800000, 0x1000);
        hose->cfg_data = ioremap(0xf0000000 + 0xc00000, 0x1000);

        u4_pcie = hose;
}

static void __init setup_u3_ht(struct pci_controller* hose)
{
        hose->ops = &u3_ht_pci_ops;

        /* We hard code the address because of the different size of
         * the reg address cell, we shall fix that by killing struct
         * reg_property and using some accessor functions instead
         */
        hose->cfg_data = ioremap(0xf2000000, 0x02000000);
        hose->cfg_addr = ioremap(0xf8070000, 0x1000);

        hose->first_busno = 0;
        hose->last_busno = 0xef;

        u3_ht = hose;
}

static int __init maple_add_bridge(struct device_node *dev)
{
        int len;
        struct pci_controller *hose;
        char* disp_name;
        const int *bus_range;
        int primary = 1;

        DBG("Adding PCI host bridge %pOF\n", dev);

        bus_range = of_get_property(dev, "bus-range", &len);
        if (bus_range == NULL || len < 2 * sizeof(int)) {
                printk(KERN_WARNING "Can't get bus-range for %pOF, assume bus 0\n",
                dev);
        }

        hose = pcibios_alloc_controller(dev);
        if (hose == NULL)
                return -ENOMEM;
        hose->first_busno = bus_range ? bus_range[0] : 0;
        hose->last_busno = bus_range ? bus_range[1] : 0xff;
        hose->controller_ops = maple_pci_controller_ops;

        disp_name = NULL;
        if (of_device_is_compatible(dev, "u3-agp")) {
                setup_u3_agp(hose);
                disp_name = "U3-AGP";
                primary = 0;
        } else if (of_device_is_compatible(dev, "u3-ht")) {
                setup_u3_ht(hose);
                disp_name = "U3-HT";
                primary = 1;
        } else if (of_device_is_compatible(dev, "u4-pcie")) {
                setup_u4_pcie(hose);
                disp_name = "U4-PCIE";
                primary = 0;
        }
        printk(KERN_INFO "Found %s PCI host bridge. Firmware bus number: %d->%d\n",
                disp_name, hose->first_busno, hose->last_busno);

        /* Interpret the "ranges" property */
        /* This also maps the I/O region and sets isa_io/mem_base */
        pci_process_bridge_OF_ranges(hose, dev, primary);

        /* Fixup "bus-range" OF property */
        fixup_bus_range(dev);

        /* Check for legacy IOs */
        isa_bridge_find_early(hose);

        return 0;
}


void maple_pci_irq_fixup(struct pci_dev *dev)
{
        DBG(" -> maple_pci_irq_fixup\n");

        /* Fixup IRQ for PCIe host */
        if (u4_pcie != NULL && dev->bus->number == 0 &&
            pci_bus_to_host(dev->bus) == u4_pcie) {
                printk(KERN_DEBUG "Fixup U4 PCIe IRQ\n");
                dev->irq = irq_create_mapping(NULL, 1);
                if (dev->irq)
                        irq_set_irq_type(dev->irq, IRQ_TYPE_LEVEL_LOW);
        }

        /* Hide AMD8111 IDE interrupt when in legacy mode so
         * the driver calls pci_get_legacy_ide_irq()
         */
        if (dev->vendor == PCI_VENDOR_ID_AMD &&
            dev->device == PCI_DEVICE_ID_AMD_8111_IDE &&
            (dev->class & 5) != 5) {
                dev->irq = 0;
        }

        DBG(" <- maple_pci_irq_fixup\n");
}

static int maple_pci_root_bridge_prepare(struct pci_host_bridge *bridge)
{
        struct pci_controller *hose = pci_bus_to_host(bridge->bus);
        struct device_node *np, *child;

        if (hose != u3_agp)
                return 0;

        /* Fixup the PCI<->OF mapping for U3 AGP due to bus renumbering. We
         * assume there is no P2P bridge on the AGP bus, which should be a
         * safe assumptions hopefully.
         */
        np = hose->dn;
        PCI_DN(np)->busno = 0xf0;
        for_each_child_of_node(np, child)
                PCI_DN(child)->busno = 0xf0;

        return 0;
}

void __init maple_pci_init(void)
{
        struct device_node *np, *root;
        struct device_node *ht = NULL;

        /* Probe root PCI hosts, that is on U3 the AGP host and the
         * HyperTransport host. That one is actually "kept" around
         * and actually added last as it's resource management relies
         * on the AGP resources to have been setup first
         */
        root = of_find_node_by_path("/");
        if (root == NULL) {
                printk(KERN_CRIT "maple_find_bridges: can't find root of device tree\n");
                return;
        }
        for_each_child_of_node(root, np) {
                if (!of_node_is_type(np, "pci") && !of_node_is_type(np, "ht"))
                        continue;
                if ((of_device_is_compatible(np, "u4-pcie") ||
                     of_device_is_compatible(np, "u3-agp")) &&
                    maple_add_bridge(np) == 0)
                        of_node_get(np);

                if (of_device_is_compatible(np, "u3-ht")) {
                        of_node_get(np);
                        ht = np;
                }
        }
        of_node_put(root);

        /* Now setup the HyperTransport host if we found any
         */
        if (ht && maple_add_bridge(ht) != 0)
                of_node_put(ht);

        ppc_md.pcibios_root_bridge_prepare = maple_pci_root_bridge_prepare;

        /* Tell pci.c to not change any resource allocations.  */
        pci_add_flags(PCI_PROBE_ONLY);
}

int maple_pci_get_legacy_ide_irq(struct pci_dev *pdev, int channel)
{
        struct device_node *np;
        unsigned int defirq = channel ? 15 : 14;
        unsigned int irq;

        if (pdev->vendor != PCI_VENDOR_ID_AMD ||
            pdev->device != PCI_DEVICE_ID_AMD_8111_IDE)
                return defirq;

        np = pci_device_to_OF_node(pdev);
        if (np == NULL) {
                printk("Failed to locate OF node for IDE %s\n",
                       pci_name(pdev));
                return defirq;
        }
        irq = irq_of_parse_and_map(np, channel & 0x1);
        if (!irq) {
                printk("Failed to map onboard IDE interrupt for channel %d\n",
                       channel);
                return defirq;
        }
        return irq;
}

static void quirk_ipr_msi(struct pci_dev *dev)
{
        /* Something prevents MSIs from the IPR from working on Bimini,
         * and the driver has no smarts to recover. So disable MSI
         * on it for now. */

        if (machine_is(maple)) {
                dev->no_msi = 1;
                dev_info(&dev->dev, "Quirk disabled MSI\n");
        }
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_OBSIDIAN,
                        quirk_ipr_msi);

struct pci_controller_ops maple_pci_controller_ops = {
};