/*
 * QEMU PIIX4 PCI Bridge Emulation
 *
 * Copyright (c) 2006 Fabrice Bellard
 * Copyright (c) 2018 Hervé Poussineau
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/irq.h"
#include "hw/southbridge/piix.h"
#include "hw/pci/pci.h"
#include "hw/isa/isa.h"
#include "hw/intc/i8259.h"
#include "hw/dma/i8257.h"
#include "hw/timer/i8254.h"
#include "hw/rtc/mc146818rtc.h"
#include "hw/ide/pci.h"
#include "migration/vmstate.h"
#include "sysemu/reset.h"
#include "sysemu/runstate.h"
#include "qom/object.h"

struct PIIX4State {
    PCIDevice dev;
    qemu_irq cpu_intr;
    qemu_irq *isa;

    RTCState rtc;
    /* Reset Control Register */
    MemoryRegion rcr_mem;
    uint8_t rcr;
};

OBJECT_DECLARE_SIMPLE_TYPE(PIIX4State, PIIX4_PCI_DEVICE)

static void piix4_set_irq(void *opaque, int irq_num, int level)
{
    int i, pic_irq, pic_level;
    PIIX4State *s = opaque;
    PCIBus *bus = pci_get_bus(&s->dev);

    /* now we change the pic irq level according to the piix irq mappings */
    /* XXX: optimize */
    pic_irq = s->dev.config[PIIX_PIRQCA + irq_num];
    if (pic_irq < ISA_NUM_IRQS) {
        /* The pic level is the logical OR of all the PCI irqs mapped to it. */
        pic_level = 0;
        for (i = 0; i < PIIX_NUM_PIRQS; i++) {
            if (pic_irq == s->dev.config[PIIX_PIRQCA + i]) {
                pic_level |= pci_bus_get_irq_level(bus, i);
            }
        }
        qemu_set_irq(s->isa[pic_irq], pic_level);
    }
}

static void piix4_isa_reset(DeviceState *dev)
{
    PIIX4State *d = PIIX4_PCI_DEVICE(dev);
    uint8_t *pci_conf = d->dev.config;

    pci_conf[0x04] = 0x07; // master, memory and I/O
    pci_conf[0x05] = 0x00;
    pci_conf[0x06] = 0x00;
    pci_conf[0x07] = 0x02; // PCI_status_devsel_medium
    pci_conf[0x4c] = 0x4d;
    pci_conf[0x4e] = 0x03;
    pci_conf[0x4f] = 0x00;
    pci_conf[0x60] = 0x0a; // PCI A -> IRQ 10
    pci_conf[0x61] = 0x0a; // PCI B -> IRQ 10
    pci_conf[0x62] = 0x0b; // PCI C -> IRQ 11
    pci_conf[0x63] = 0x0b; // PCI D -> IRQ 11
    pci_conf[0x69] = 0x02;
    pci_conf[0x70] = 0x80;
    pci_conf[0x76] = 0x0c;
    pci_conf[0x77] = 0x0c;
    pci_conf[0x78] = 0x02;
    pci_conf[0x79] = 0x00;
    pci_conf[0x80] = 0x00;
    pci_conf[0x82] = 0x00;
    pci_conf[0xa0] = 0x08;
    pci_conf[0xa2] = 0x00;
    pci_conf[0xa3] = 0x00;
    pci_conf[0xa4] = 0x00;
    pci_conf[0xa5] = 0x00;
    pci_conf[0xa6] = 0x00;
    pci_conf[0xa7] = 0x00;
    pci_conf[0xa8] = 0x0f;
    pci_conf[0xaa] = 0x00;
    pci_conf[0xab] = 0x00;
    pci_conf[0xac] = 0x00;
    pci_conf[0xae] = 0x00;
}

static int piix4_ide_post_load(void *opaque, int version_id)
{
    PIIX4State *s = opaque;

    if (version_id == 2) {
        s->rcr = 0;
    }

    return 0;
}

static const VMStateDescription vmstate_piix4 = {
    .name = "PIIX4",
    .version_id = 3,
    .minimum_version_id = 2,
    .post_load = piix4_ide_post_load,
    .fields = (VMStateField[]) {
        VMSTATE_PCI_DEVICE(dev, PIIX4State),
        VMSTATE_UINT8_V(rcr, PIIX4State, 3),
        VMSTATE_END_OF_LIST()
    }
};

static void piix4_request_i8259_irq(void *opaque, int irq, int level)
{
    PIIX4State *s = opaque;
    qemu_set_irq(s->cpu_intr, level);
}

static void piix4_set_i8259_irq(void *opaque, int irq, int level)
{
    PIIX4State *s = opaque;
    qemu_set_irq(s->isa[irq], level);
}

static void piix4_rcr_write(void *opaque, hwaddr addr, uint64_t val,
                            unsigned int len)
{
    PIIX4State *s = opaque;

    if (val & 4) {
        qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
        return;
    }

    s->rcr = val & 2; /* keep System Reset type only */
}

static uint64_t piix4_rcr_read(void *opaque, hwaddr addr, unsigned int len)
{
    PIIX4State *s = opaque;

    return s->rcr;
}

static const MemoryRegionOps piix4_rcr_ops = {
    .read = piix4_rcr_read,
    .write = piix4_rcr_write,
    .endianness = DEVICE_LITTLE_ENDIAN,
    .impl = {
        .min_access_size = 1,
        .max_access_size = 1,
    },
};

static void piix4_realize(PCIDevice *dev, Error **errp)
{
    PIIX4State *s = PIIX4_PCI_DEVICE(dev);
    ISABus *isa_bus;
    qemu_irq *i8259_out_irq;

    isa_bus = isa_bus_new(DEVICE(dev), pci_address_space(dev),
                          pci_address_space_io(dev), errp);
    if (!isa_bus) {
        return;
    }

    qdev_init_gpio_in_named(DEVICE(dev), piix4_set_i8259_irq,
                            "isa", ISA_NUM_IRQS);
    qdev_init_gpio_out_named(DEVICE(dev), &s->cpu_intr,
                             "intr", 1);

    memory_region_init_io(&s->rcr_mem, OBJECT(dev), &piix4_rcr_ops, s,
                          "reset-control", 1);
    memory_region_add_subregion_overlap(pci_address_space_io(dev),
                                        PIIX_RCR_IOPORT, &s->rcr_mem, 1);

    /* initialize i8259 pic */
    i8259_out_irq = qemu_allocate_irqs(piix4_request_i8259_irq, s, 1);
    s->isa = i8259_init(isa_bus, *i8259_out_irq);

    /* initialize ISA irqs */
    isa_bus_irqs(isa_bus, s->isa);

    /* initialize pit */
    i8254_pit_init(isa_bus, 0x40, 0, NULL);

    /* DMA */
    i8257_dma_init(isa_bus, 0);

    /* RTC */
    qdev_prop_set_int32(DEVICE(&s->rtc), "base_year", 2000);
    if (!qdev_realize(DEVICE(&s->rtc), BUS(isa_bus), errp)) {
        return;
    }
    s->rtc.irq = isa_get_irq(ISA_DEVICE(&s->rtc), s->rtc.isairq);
}

static void piix4_init(Object *obj)
{
    PIIX4State *s = PIIX4_PCI_DEVICE(obj);

    object_initialize(&s->rtc, sizeof(s->rtc), TYPE_MC146818_RTC);
}

static void piix4_class_init(ObjectClass *klass, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(klass);
    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);

    k->realize = piix4_realize;
    k->vendor_id = PCI_VENDOR_ID_INTEL;
    k->device_id = PCI_DEVICE_ID_INTEL_82371AB_0;
    k->class_id = PCI_CLASS_BRIDGE_ISA;
    dc->reset = piix4_isa_reset;
    dc->desc = "ISA bridge";
    dc->vmsd = &vmstate_piix4;
    /*
     * Reason: part of PIIX4 southbridge, needs to be wired up,
     * e.g. by mips_malta_init()
     */
    dc->user_creatable = false;
    dc->hotpluggable = false;
}

static const TypeInfo piix4_info = {
    .name          = TYPE_PIIX4_PCI_DEVICE,
    .parent        = TYPE_PCI_DEVICE,
    .instance_size = sizeof(PIIX4State),
    .instance_init = piix4_init,
    .class_init    = piix4_class_init,
    .interfaces = (InterfaceInfo[]) {
        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
        { },
    },
};

static void piix4_register_types(void)
{
    type_register_static(&piix4_info);
}

type_init(piix4_register_types)

static int pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num)
{
    int slot;

    slot = PCI_SLOT(pci_dev->devfn);

    switch (slot) {
    /* PIIX4 USB */
    case 10:
        return 3;
    /* AMD 79C973 Ethernet */
    case 11:
        return 1;
    /* Crystal 4281 Sound */
    case 12:
        return 2;
    /* PCI slot 1 to 4 */
    case 18 ... 21:
        return ((slot - 18) + irq_num) & 0x03;
    /* Unknown device, don't do any translation */
    default:
        return irq_num;
    }
}

DeviceState *piix4_create(PCIBus *pci_bus, ISABus **isa_bus, I2CBus **smbus)
{
    PIIX4State *s;
    PCIDevice *pci;
    DeviceState *dev;
    int devfn = PCI_DEVFN(10, 0);

    pci = pci_create_simple_multifunction(pci_bus, devfn,  true,
                                          TYPE_PIIX4_PCI_DEVICE);
    dev = DEVICE(pci);
    s = PIIX4_PCI_DEVICE(pci);
    if (isa_bus) {
        *isa_bus = ISA_BUS(qdev_get_child_bus(dev, "isa.0"));
    }

    pci = pci_create_simple(pci_bus, devfn + 1, "piix4-ide");
    pci_ide_create_devs(pci);

    pci_create_simple(pci_bus, devfn + 2, "piix4-usb-uhci");
    if (smbus) {
        *smbus = piix4_pm_init(pci_bus, devfn + 3, 0x1100,
                               qdev_get_gpio_in_named(dev, "isa", 9),
                               NULL, 0, NULL);
    }

    pci_bus_irqs(pci_bus, piix4_set_irq, pci_slot_get_pirq, s, PIIX_NUM_PIRQS);

    return dev;
}