/*
 * 86Box    A hypervisor and IBM PC system emulator that specializes in
 *          running old operating systems and software designed for IBM
 *          PC systems and compatibles from 1981 through fairly recent
 *          system designs based on the PCI bus.
 *
 *          This file is part of the 86Box distribution.
 *
 *          Emulation of the NatSemi PC87309 Super I/O chip.
 *
 * Authors: Miran Grca, <mgrca8@gmail.com>
 *
 *          Copyright 2020-2025 Miran Grca.
 */
#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#define HAVE_STDARG_H
#include <86box/86box.h>
#include <86box/io.h>
#include <86box/timer.h>
#include <86box/device.h>
#include <86box/lpt.h>
#include <86box/machine.h>
#include <86box/mem.h>
#include <86box/nvr.h>
#include <86box/pci.h>
#include <86box/rom.h>
#include <86box/serial.h>
#include <86box/fdd.h>
#include <86box/fdc.h>
#include <86box/keyboard.h>
#include <86box/sio.h>
#include <86box/plat_fallthrough.h>
#include "cpu.h"

typedef struct pc87309_t {
    uint8_t   id;
    uint8_t   baddr;
    uint8_t   pm_idx;
    uint8_t   regs[48];
    uint8_t   ld_regs[256][208];
    uint8_t   pm[8];
    uint16_t  superio_base;
    uint16_t  pm_base;
    int       cur_reg;
    void     *kbc;
    fdc_t    *fdc;
    serial_t *uart[2];
} pc87309_t;

enum {
    LD_FDC   = 0,
    LD_LPT,
    LD_UART2,
    LD_UART1,
    LD_PM,
    LD_MOUSE,
    LD_KBD
} pc87309_ld_t;

#define LD_MIN LD_FDC
#define LD_MAX LD_MOUSE

static void    fdc_handler(pc87309_t *dev);
static void    lpt1_handler(pc87309_t *dev);
static void    serial_handler(pc87309_t *dev, int uart);
static void    kbc_handler(pc87309_t *dev);
static void    pc87309_write(uint16_t port, uint8_t val, void *priv);
static uint8_t pc87309_read(uint16_t port, void *priv);

#ifdef ENABLE_PC87309_LOG
int pc87309_do_log = ENABLE_PC87309_LOG;

static void
pc87309_log(const char *fmt, ...)
{
    va_list ap;

    if (pc87309_do_log) {
        va_start(ap, fmt);
        pclog_ex(fmt, ap);
        va_end(ap);
    }
}
#else
#    define pc87309_log(fmt, ...)
#endif

static void
pc87309_pm_write(uint16_t port, uint8_t val, void *priv)
{
    pc87309_t *dev = (pc87309_t *) priv;

    if (port & 1)
        dev->pm[dev->pm_idx] = val;
    else {
        dev->pm_idx = val & 0x07;

        switch (dev->pm_idx) {
            case 0x00:
                fdc_handler(dev);
                lpt1_handler(dev);
                serial_handler(dev, 1);
                serial_handler(dev, 0);
                break;

            default:
                break;
        }
    }
}

uint8_t
pc87309_pm_read(uint16_t port, void *priv)
{
    const pc87309_t *dev = (pc87309_t *) priv;

    if (port & 1)
        return dev->pm[dev->pm_idx];
    else
        return dev->pm_idx;
}

static void
pc87309_pm_remove(pc87309_t *dev)
{
    if (dev->pm_base != 0xffff) {
        io_removehandler(dev->pm_base, 0x0008,
                         pc87309_pm_read, NULL, NULL, pc87309_pm_write, NULL, NULL, dev);
        dev->pm_base = 0xffff;
    }
}

static void
pc87309_pm_init(pc87309_t *dev, uint16_t addr)
{
    dev->pm_base = addr;

    io_sethandler(dev->pm_base, 0x0008,
                  pc87309_pm_read, NULL, NULL, pc87309_pm_write, NULL, NULL, dev);
}

static void
kbc_handler(pc87309_t *dev)
{
    uint8_t  active   = (dev->ld_regs[LD_KBD][0x00] & 0x01) &&
                        (dev->pm[0x00] & 0x01);
    uint8_t  active_2 = dev->ld_regs[LD_MOUSE][0x00] & 0x01;
    uint8_t  irq      = (dev->ld_regs[LD_KBD][0x40] & 0x0f);
    uint8_t  irq_2    = (dev->ld_regs[LD_MOUSE][0x40] & 0x0f);
    uint16_t addr     = (dev->ld_regs[LD_KBD][0x30] << 8) |
                        dev->ld_regs[LD_KBD][0x31];
    uint16_t addr_2   = (dev->ld_regs[LD_KBD][0x32] << 8) |
                        dev->ld_regs[LD_KBD][0x33];

    pc87309_log("%02X, %02X, %02X, %02X, %04X, %04X\n",
                active, active_2, irq, irq_2, addr, addr_2);

    if (addr <= 0xfff8) {
        pc87309_log("Enabling KBC #1 on %04X...\n", addr);
        kbc_at_port_handler(0, active, addr,   dev->kbc);
    }

    if (addr_2 <= 0xfff8) {
        pc87309_log("Enabling KBC #2 on %04X...\n", addr_2);
        kbc_at_port_handler(1, active, addr_2, dev->kbc);
    }

    kbc_at_set_irq(0, active               ? irq   : 0xffff, dev->kbc);
    kbc_at_set_irq(1, (active && active_2) ? irq_2 : 0xffff, dev->kbc);
}

static void
fdc_handler(pc87309_t *dev)
{
    fdc_remove(dev->fdc);

    uint8_t  active = (dev->ld_regs[LD_FDC][0x00] & 0x01) &&
                      (dev->pm[0x00] & 0x08);
    uint8_t  irq    = (dev->ld_regs[LD_FDC][0x40] & 0x0f);
    uint16_t addr   = ((dev->ld_regs[LD_FDC][0x30] << 8) |
                      dev->ld_regs[LD_FDC][0x31]) & 0xfff8;

    if (active && (addr <= 0xfff8)) {
        pc87309_log("Enabling FDC on %04X, IRQ %i...\n", addr, irq);
        fdc_set_base(dev->fdc, addr);
        fdc_set_irq(dev->fdc, irq);
    }
}

static void
lpt1_handler(pc87309_t *dev)
{
    uint8_t  active = (dev->ld_regs[LD_LPT][0x00] & 0x01) &&
                      (dev->pm[0x00] & 0x10);
    uint8_t  irq    = (dev->ld_regs[LD_LPT][0x40] & 0x0f);
    uint16_t addr   = (dev->ld_regs[LD_LPT][0x30] << 8) |
                      dev->ld_regs[LD_LPT][0x31];

    if (active && (addr <= 0xfffc)) {
        pc87309_log("Enabling LPT1 on %04X...\n", addr);
        lpt1_setup(addr);
    } else
        lpt1_setup(0xffff);

    lpt1_irq(irq);
}

static void
serial_handler(pc87309_t *dev, int uart)
{
    serial_remove(dev->uart[uart]);

    uint8_t  active = (dev->ld_regs[LD_UART1 - uart][0x00] & 0x01) &&
                      (dev->pm[0x00] & (1 << (6 - uart)));
    uint8_t  irq    = (dev->ld_regs[LD_UART1 - uart][0x40] & 0x0f);
    uint16_t addr   = (dev->ld_regs[LD_UART1 - uart][0x30] << 8) |
                      dev->ld_regs[LD_UART1 - uart][0x31];

    if (active && (addr <= 0xfff8)) {
        pc87309_log("Enabling COM%i on %04X...\n", uart + 1, addr);
        serial_setup(dev->uart[uart], addr, irq);
    } else
        serial_setup(dev->uart[uart], 0x0000, irq);
}

static void
pm_handler(pc87309_t *dev)
{
    pc87309_pm_remove(dev);

    uint8_t  active = (dev->ld_regs[LD_PM][0x00] & 0x01);
    uint16_t addr   = (dev->ld_regs[LD_PM][0x30] << 8) |
                      dev->ld_regs[LD_PM][0x31];

    if (active) {
        pc87309_log("Enabling power management on %04X...\n", addr);
        pc87309_pm_init(dev, addr);
    }
}

static void
superio_handler(pc87309_t *dev)
{
    if (dev->superio_base != 0x0000)
        io_removehandler(dev->superio_base, 0x0002,
                         pc87309_read, NULL, NULL,
                         pc87309_write, NULL, NULL, dev);

    switch (dev->regs[0x21] & 0x0b) {
        default:
            dev->superio_base = 0x0000;
            break;
        case 0x02:
        case 0x08: case 0x0a:
            dev->superio_base = 0x015c;
            break;
        case 0x03:
        case 0x09: case 0x0b:
            dev->superio_base = 0x002e;
            break;
    }

    if (dev->superio_base != 0x0000) {
        pc87309_log("Enabling Super I/O on %04X...\n", dev->superio_base);
        io_sethandler(dev->superio_base, 0x0002,
                      pc87309_read, NULL, NULL,
                      pc87309_write, NULL, NULL, dev);
    }
}

static void
pc87309_write(uint16_t port, uint8_t val, void *priv)
{
    pc87309_t *dev   = (pc87309_t *) priv;
    uint8_t    ld    = dev->regs[0x07];
    uint8_t    reg   = dev->cur_reg - 0x30;
    uint8_t    index = (port & 1) ? 0 : 1;
    uint8_t    old   = dev->regs[dev->cur_reg];

    if (index) {
        dev->cur_reg = val;
        return;
    } else {
#ifdef ENABLE_PC87309_LOG
        if (dev->cur_reg >= 0x30)
            pc87309_log("[%04X:%08X] [W] (%04X) %02X:%02X = %02X\n",
                        CS, cpu_state.pc, port, ld, dev->cur_reg, val);
        else
            pc87309_log("[%04X:%08X] [W] (%04X)    %02X = %02X\n",
                        CS, cpu_state.pc, port,     dev->cur_reg, val);
#endif
        switch (dev->cur_reg) {
            case 0x00:
            case 0x02: case 0x03:
            case 0x06: case 0x07:
                dev->regs[dev->cur_reg] = val;
                break;
            case 0x21:
                dev->regs[dev->cur_reg] = val;
                fdc_toggle_flag(dev->fdc, FDC_FLAG_PS2_MCA, !(val & 0x04));
                superio_handler(dev);
                break;
            case 0x22:
                dev->regs[dev->cur_reg] = val;
                break;
            default:
                if (dev->cur_reg >= 0x30)
                    old = dev->ld_regs[ld][reg];
                break;
        }
    }

    switch (dev->cur_reg) {
        case 0x30:
            switch (ld) {
                default:
                    break;
                case LD_KBD: case LD_MOUSE:
                    dev->ld_regs[ld][reg] = val;
                    kbc_handler(dev);
                    break;
                case LD_FDC:
                    dev->ld_regs[ld][reg] = val;
                    fdc_handler(dev);
                    break;
                case LD_LPT:
                    dev->ld_regs[ld][reg] = val;
                    lpt1_handler(dev);
                    break;
                case LD_UART2:
                    dev->ld_regs[ld][reg] = val;
                    serial_handler(dev, 1);
                    break;
                case LD_UART1:
                    dev->ld_regs[ld][reg] = val;
                    serial_handler(dev, 0);
                    break;
                case LD_PM:
                    dev->ld_regs[ld][reg] = val;
                    pm_handler(dev);
                    break;
            }
            break;
        /* I/O Range Check. */
        case 0x31:
            switch (ld) {
                default:
                    break;
                case LD_MIN ... LD_MAX:
                    if (ld != LD_MOUSE)
                        dev->ld_regs[ld][reg] = val;
                    break;
            }
            break;
        /* Base Address 0 MSB. */
        case 0x60:
            switch (ld) {
                default:
                    break;
                case LD_KBD:
                    dev->ld_regs[ld][reg] = val;
                    kbc_handler(dev);
                    break;
                case LD_FDC:
                    dev->ld_regs[ld][reg] = val;
                    fdc_handler(dev);
                    break;
                case LD_LPT:
                    dev->ld_regs[ld][reg] = (old & 0xfc) | (val & 0x03);
                    lpt1_handler(dev);
                    break;
                case LD_UART2:
                    dev->ld_regs[ld][reg] = val;
                    serial_handler(dev, 1);
                    break;
                case LD_UART1:
                    dev->ld_regs[ld][reg] = val;
                    serial_handler(dev, 0);
                    break;
                case LD_PM:
                    dev->ld_regs[ld][reg] = val;
                    pm_handler(dev);
                    break;
            }
            break;
        /* Base Address 0 LSB. */
        case 0x61:
            switch (ld) {
                default:
                    break;
                case LD_KBD:
                    dev->ld_regs[ld][reg] = (old & 0x04) | (val & 0xfb);
                    kbc_handler(dev);
                    break;
                case LD_FDC:
                    dev->ld_regs[ld][reg] = (old & 0x07) | (val & 0xf8);
                    fdc_handler(dev);
                    break;
                case LD_LPT:
                    dev->ld_regs[ld][reg] = (old & 0x03) | (val & 0xfc);
                    lpt1_handler(dev);
                    break;
                case LD_UART2:
                    dev->ld_regs[ld][reg] = (old & 0x07) | (val & 0xf8);
                    serial_handler(dev, 1);
                    break;
                case LD_UART1:
                    dev->ld_regs[ld][reg] = (old & 0x07) | (val & 0xf8);
                    serial_handler(dev, 0);
                    break;
                case LD_PM:
                    dev->ld_regs[ld][reg] = (old & 0x01) | (val & 0xfe);
                    pm_handler(dev);
                    break;
            }
            break;
        /* Base Address 1 MSB (undocumented for Logical Device 7). */
        case 0x62:
            switch (ld) {
                default:
                    break;
                case LD_KBD:
                    dev->ld_regs[ld][reg] = val;
                    kbc_handler(dev);
                    break;
            }
            break;
        /* Base Address 1 LSB (undocumented for Logical Device 7). */
        case 0x63:
            switch (ld) {
                default:
                    break;
                case LD_KBD:
                    dev->ld_regs[ld][reg] = (old & 0x04) | (val & 0xfb);
                    kbc_handler(dev);
                    break;
            }
            break;
        /* Interrupt Select. */
        case 0x70:
            switch (ld) {
                default:
                    break;
                case LD_KBD: case LD_MOUSE:
                    dev->ld_regs[ld][reg] = val;
                    kbc_handler(dev);
                    break;
                case LD_FDC:
                    dev->ld_regs[ld][reg] = val;
                    fdc_handler(dev);
                    break;
                case LD_LPT:
                    dev->ld_regs[ld][reg] = val;
                    lpt1_handler(dev);
                    break;
                case LD_UART2:
                    dev->ld_regs[ld][reg] = val;
                    serial_handler(dev, 1);
                    break;
                case LD_UART1:
                    dev->ld_regs[ld][reg] = val;
                    serial_handler(dev, 0);
                    break;
            }
            break;
        /* Interrupt Type. */
        case 0x71:
            switch (ld) {
                default:
                    break;
                case LD_MIN ... LD_MAX:
                    if ((ld == LD_KBD) || (ld == LD_MOUSE))
                        dev->ld_regs[ld][reg] = (old & 0xfc) | (val & 0x03);
                    else
                        dev->ld_regs[ld][reg] = (old & 0xfd) | (val & 0x02);
                    break;
            }
            break;
        /* DMA Channel Select 0. */
        case 0x74:
            switch (ld) {
                default:
                    break;
                case LD_FDC:
                    dev->ld_regs[ld][reg] = val;
                    fdc_handler(dev);
                    break;
                case LD_LPT:
                    dev->ld_regs[ld][reg] = val;
                    lpt1_handler(dev);
                    break;
                case LD_UART2:
                    dev->ld_regs[ld][reg] = val;
                    break;
            }
            break;
        /* DMA Channel Select 1. */
        case 0x75:
            switch (ld) {
                default:
                    break;
                case LD_UART2:
                    dev->ld_regs[ld][reg] = val;
                    break;
            }
            break;
        /* Configuration Register 0. */
        case 0xf0:
            switch (ld) {
                default:
                    break;
                case LD_KBD:
                    dev->ld_regs[ld][reg] = val;
                    break;
                case LD_FDC:
                    dev->ld_regs[ld][reg] = val;
                    fdc_update_densel_polarity(dev->fdc, (val & 0x20) ? 1 : 0);
                    fdc_update_enh_mode(dev->fdc, (val & 0x40) ? 1 : 0);
                    break;
                case LD_LPT:
                    dev->ld_regs[ld][reg] = val;
                    lpt1_handler(dev);
                    break;
                case LD_UART2: case LD_UART1:
                    dev->ld_regs[ld][reg] = val;
                    break;
            }
            break;
        /* Configuration Register 1. */
        case 0xf1:
            switch (ld) {
                default:
                    break;
                case LD_FDC:
                    dev->ld_regs[ld][reg] = val;
                    break;
            }
            break;

        default:
            break;
    }
}

static uint8_t
pc87309_read(uint16_t port, void *priv)
{
    const pc87309_t *dev   = (pc87309_t *) priv;
    uint8_t          ld    = dev->regs[0x07];
    uint8_t          reg   = dev->cur_reg - 0x30;
    uint8_t          index = (port & 1) ? 0 : 1;
    uint8_t          ret   = 0xff;

    if (index)
        ret = dev->cur_reg;
    else {
        if (dev->cur_reg >= 0x30)
            ret = dev->ld_regs[ld][reg];
        /* Write-only registers. */
        else if ((dev->cur_reg == 0x00) ||
                 (dev->cur_reg == 0x02) || (dev->cur_reg == 0x03))
            ret = 0x00;
        else
            ret = dev->regs[dev->cur_reg];
#ifdef ENABLE_PC87309_LOG
        if (dev->cur_reg >= 0x30)
            pc87309_log("[%04X:%08X] [R] (%04X) %02X:%02X = %02X\n",
                        CS, cpu_state.pc, port, ld, dev->cur_reg, ret);
        else
            pc87309_log("[%04X:%08X] [R] (%04X)    %02X = %02X\n",
                        CS, cpu_state.pc, port,     dev->cur_reg, ret);
#endif
    }

    return ret;
}

void
pc87309_reset(void *priv)
{
    pc87309_t *dev = (pc87309_t *) priv;

    memset(dev->regs, 0x00, 0x30);
    for (uint16_t i = 0; i < 256; i++)
        memset(dev->ld_regs[i], 0x00, 0xd0);
    memset(dev->pm, 0x00, 0x08);

    dev->regs[0x20] = dev->id;
    dev->regs[0x21] = 0x04 | dev->baddr;

    dev->ld_regs[LD_KBD  ][0x00] = 0x01;
    dev->ld_regs[LD_KBD  ][0x31] = 0x60;
    dev->ld_regs[LD_KBD  ][0x33] = 0x64;
    dev->ld_regs[LD_KBD  ][0x40] = 0x01;
    dev->ld_regs[LD_KBD  ][0x41] = 0x02;
    dev->ld_regs[LD_KBD  ][0x44] = 0x04;
    dev->ld_regs[LD_KBD  ][0x45] = 0x04;
    dev->ld_regs[LD_KBD  ][0xc0] = 0x40;

    dev->ld_regs[LD_MOUSE][0x40] = 0x0c;
    dev->ld_regs[LD_MOUSE][0x41] = 0x02;
    dev->ld_regs[LD_MOUSE][0x44] = 0x04;
    dev->ld_regs[LD_MOUSE][0x45] = 0x04;

    dev->ld_regs[LD_FDC  ][0x01] = 0x01;
    dev->ld_regs[LD_FDC  ][0x30] = 0x03;
    dev->ld_regs[LD_FDC  ][0x31] = 0xf0;
    dev->ld_regs[LD_FDC  ][0x32] = 0x03;
    dev->ld_regs[LD_FDC  ][0x33] = 0xf7;
    dev->ld_regs[LD_FDC  ][0x40] = 0x06;
    dev->ld_regs[LD_FDC  ][0x41] = 0x03;
    dev->ld_regs[LD_FDC  ][0x44] = 0x02;
    dev->ld_regs[LD_FDC  ][0x45] = 0x04;
    dev->ld_regs[LD_FDC  ][0xc0] = 0x02;

    dev->ld_regs[LD_LPT  ][0x30] = 0x02;
    dev->ld_regs[LD_LPT  ][0x31] = 0x78;
    dev->ld_regs[LD_LPT  ][0x40] = 0x07;
    dev->ld_regs[LD_LPT  ][0x44] = 0x04;
    dev->ld_regs[LD_LPT  ][0x45] = 0x04;
    dev->ld_regs[LD_LPT  ][0xc0] = 0xf2;

    dev->ld_regs[LD_UART2][0x30] = 0x02;
    dev->ld_regs[LD_UART2][0x31] = 0xf8;
    dev->ld_regs[LD_UART2][0x40] = 0x03;
    dev->ld_regs[LD_UART2][0x41] = 0x03;
    dev->ld_regs[LD_UART2][0x44] = 0x04;
    dev->ld_regs[LD_UART2][0x45] = 0x04;
    dev->ld_regs[LD_UART2][0xc0] = 0x02;

    dev->ld_regs[LD_UART1][0x30] = 0x03;
    dev->ld_regs[LD_UART1][0x31] = 0xf8;
    dev->ld_regs[LD_UART1][0x40] = 0x04;
    dev->ld_regs[LD_UART1][0x41] = 0x03;
    dev->ld_regs[LD_UART1][0x44] = 0x04;
    dev->ld_regs[LD_UART1][0x45] = 0x04;
    dev->ld_regs[LD_UART1][0xc0] = 0x02;

    dev->ld_regs[LD_PM   ][0x44] = 0x04;
    dev->ld_regs[LD_PM   ][0x45] = 0x04;

    dev->pm[0] = 0x79;
    dev->pm[4] = 0x0e;

    dev->pm_base = 0xffff;

    /*
        0 = 360 rpm @ 500 kbps for 3.5"
        1 = Default, 300 rpm @ 500, 300, 250, 1000 kbps for 3.5"
    */
    fdc_toggle_flag(dev->fdc, FDC_FLAG_PS2_MCA, 0);
    fdc_reset(dev->fdc);

    kbc_handler(dev);
    fdc_handler(dev);
    lpt1_handler(dev);
    serial_handler(dev, 0);
    serial_handler(dev, 1);
    pm_handler(dev);
    superio_handler(dev);
}

static void
pc87309_close(void *priv)
{
    pc87309_t *dev = (pc87309_t *) priv;

    free(dev);
}

static void *
pc87309_init(const device_t *info)
{
    pc87309_t *dev = (pc87309_t *) calloc(1, sizeof(pc87309_t));

    dev->id = info->local & 0xff;

    dev->fdc = device_add(&fdc_at_nsc_device);

    dev->uart[0] = device_add_inst(&ns16550_device, 1);
    dev->uart[1] = device_add_inst(&ns16550_device, 2);

    switch (info->local & PCX730X_KBC) {
        default:
        case PCX730X_AMI:
            dev->kbc = device_add(&keyboard_ps2_intel_ami_pci_device);
            break;
        /* Optiplex! */
        case PCX730X_PHOENIX_42:
            dev->kbc = device_add(&keyboard_ps2_phoenix_device);
            break;
        case PCX730X_PHOENIX_42I:
            dev->kbc = device_add(&keyboard_ps2_phoenix_pci_device);
            break;
    }

    if (info->local & PCX730X_15C)
        dev->baddr = 0x0a;
    else
        dev->baddr = 0x0b;

    pc87309_reset(dev);

    return dev;
}

const device_t pc87309_device = {
    .name          = "National Semiconductor PC87309 Super I/O",
    .internal_name = "pc87309",
    .flags         = 0,
    .local         = 0,
    .init          = pc87309_init,
    .close         = pc87309_close,
    .reset         = pc87309_reset,
    .available     = NULL,
    .speed_changed = NULL,
    .force_redraw  = NULL,
    .config        = NULL
};