/*
 * 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.
 *
 *          Implementation of the ALi M1429 chipset.
 *
 * Note:    This chipset has no datasheet, everything were done via
 *          reverse engineering the BIOS of various machines using it.
 *
 * Authors: Tiseno100,
 *          Miran Grca, <mgrca8@gmail.com>
 *
 *          Copyright 2020-2021 Tiseno100.
 *          Copyright 2021      Miran Grca.
 */

/*
    ALi M1429/M1429G Configuration Registers

    Notes: Incorporated sometimes with a M1435 PCI-to-VLB Bridge
           M1429G is just a 1429 with Green Functionality
           SMM in it's entirety needs more research

    Warning: Register documentation may be inaccurate!

    Register 03h: Write C5h to unlock the configuration registers

    Register 10h & 11h: DRAM Bank Configuration

    Register 12h:
    Bit 2: Memory Remapping Enable (128KB)

    Register 13h:
    Bit 7: Shadow RAM Enable for F8000-FFFFF
    Bit 6: Shadow RAM Enable for F0000-F7FFF
    Bit 5: Shadow RAM Enable for E8000-FFFFF
    Bit 4: Shadow RAM Enable for E0000-F7FFF
    Bit 3: Shadow RAM Enable for D8000-FFFFF
    Bit 2: Shadow RAM Enable for D0000-F7FFF
    Bit 1: Shadow RAM Enable for C8000-FFFFF
    Bit 0: Shadow RAM Enable for C0000-F7FFF

    Register 14h:
    Bit 1: Shadow RAM Write for Enabled Segments
    Bit 0: Shadow RAM Read for Enabled Segments

    Register 18h:
    Bit 6-5-4 (Cache Size)
        0 0 0 32KB
        0 0 1 128KB
        0 1 0 256KB
        0 1 1 512KB
        1 0 0 64KB
        1 0 1 256KB
        1 1 0 512KB
        1 1 1 1MB

    Bit 1: L2 Cache Enable

    Register 20h:
    Bits 2-1-0: Bus Clock Speed
         0 0 0: 7.1519Mhz (ATCLK2)
         0 0 1: CLK2IN/4
         0 1 0: CLK2IN/5
         0 1 1: CLK2IN/6
         1 0 0: CLK2IN/8
         1 0 1: CLK2IN/10
         1 1 0: CLK2IN/12

*/
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#define HAVE_STDARG_H
#include <86box/86box.h>
#include "cpu.h"
#include <86box/timer.h>
#include <86box/io.h>
#include <86box/device.h>

#include <86box/apm.h>
#include <86box/mem.h>
#include <86box/fdd.h>
#include <86box/fdc.h>
#include <86box/port_92.h>
#include <86box/smram.h>
#include <86box/chipset.h>

#define GREEN dev->is_g /* Is G Variant */

#ifdef ENABLE_ALI1429_LOG
int ali1429_do_log = ENABLE_ALI1429_LOG;

static void
ali1429_log(const char *fmt, ...)
{
    va_list ap;

    if (ali1429_do_log) {
        va_start(ap, fmt);
        pclog_ex(fmt, ap);
        va_end(ap);
    }
}
#else
#    define ali1429_log(fmt, ...)
#endif

typedef struct ali_1429_t {
    uint8_t is_g;
    uint8_t index;
    uint8_t cfg_locked;
    uint8_t reg_57h;
    uint8_t regs[90];
} ali1429_t;

static void
ali1429_shadow_recalc(ali1429_t *dev)
{
    uint32_t base;
    uint32_t can_write;
    uint32_t can_read;

    shadowbios       = (dev->regs[0x13] & 0x40) && (dev->regs[0x14] & 0x01);
    shadowbios_write = (dev->regs[0x13] & 0x40) && (dev->regs[0x14] & 0x02);

    can_write = (dev->regs[0x14] & 0x02) ? MEM_WRITE_INTERNAL : MEM_WRITE_EXTANY;
    can_read  = (dev->regs[0x14] & 0x01) ? MEM_READ_INTERNAL : MEM_READ_EXTANY;

    for (uint8_t i = 0; i < 8; i++) {
        base = 0xc0000 + (i << 15);

        if (dev->regs[0x13] & (1 << i))
            mem_set_mem_state_both(base, 0x8000, can_read | can_write);
        else
            mem_set_mem_state_both(base, 0x8000, MEM_READ_EXTANY | MEM_WRITE_EXTANY);
    }

    flushmmucache_nopc();
}

static void
ali1429_write(uint16_t addr, uint8_t val, void *priv)
{
    ali1429_t *dev = (ali1429_t *) priv;

    switch (addr) {
        case 0x22:
            dev->index = val;
            break;

        case 0x23:
#ifdef ENABLE_ALI1429_LOG
            if (dev->index != 0x03)
                ali1429_log("M1429: dev->regs[%02x] = %02x\n", dev->index, val);
#endif

            if (dev->index == 0x03)
                dev->cfg_locked = (val != 0xc5);

            if (!dev->cfg_locked) {
                ali1429_log("M1429: dev->regs[%02x] = %02x\n", dev->index, val);

                /* Common M1429 Registers */
                switch (dev->index) {
                    case 0x10:
                    case 0x11:
                        dev->regs[dev->index] = val;
                        break;

                    case 0x12:
                        dev->regs[dev->index] = val;
                        if (val & 4)
                            mem_remap_top(128);
                        else
                            mem_remap_top(0);
                        break;

                    case 0x13:
                    case 0x14:
                        dev->regs[dev->index] = val;
                        ali1429_shadow_recalc(dev);
                        break;

                    case 0x15:
                    case 0x16:
                    case 0x17:
                        dev->regs[dev->index] = val;
                        break;

                    case 0x18:
                        dev->regs[dev->index] = (val & 0x8f) | 0x20;
                        cpu_cache_ext_enabled = !!(val & 2);
                        cpu_update_waitstates();
                        break;

                    case 0x19:
                    case 0x1a:
                    case 0x1e:
                        dev->regs[dev->index] = val;
                        break;

                    case 0x20:
                        dev->regs[dev->index] = val;

                        switch (val & 7) {
                            case 0:
                            case 7: /* Illegal */
                                cpu_set_isa_speed(7159091);
                                break;

                            case 1:
                                cpu_set_isa_speed(cpu_busspeed / 4);
                                break;

                            case 2:
                                cpu_set_isa_speed(cpu_busspeed / 5);
                                break;

                            case 3:
                                cpu_set_isa_speed(cpu_busspeed / 6);
                                break;

                            case 4:
                                cpu_set_isa_speed(cpu_busspeed / 8);
                                break;

                            case 5:
                                cpu_set_isa_speed(cpu_busspeed / 10);
                                break;

                            case 6:
                                cpu_set_isa_speed(cpu_busspeed / 12);
                                break;
                            default:
                                break;
                        }
                        break;

                    case 0x21 ... 0x27:
                        dev->regs[dev->index] = val;
                        break;
                    default:
                        break;
                }

                /* M1429G Only Registers */
                if (GREEN) {
                    switch (dev->index) {
                        case 0x30 ... 0x41:
                        case 0x43:
                        case 0x45:
                        case 0x4a:
                            dev->regs[dev->index] = val;
                            break;

                        case 0x57:
                            dev->reg_57h = val;
                            break;
                        default:
                            break;
                    }
                }
            }
            break;
        default:
            break;
    }
}

static uint8_t
ali1429_read(uint16_t addr, void *priv)
{
    const ali1429_t *dev = (ali1429_t *) priv;
    uint8_t          ret = 0xff;

    if ((addr == 0x23) && (dev->index >= 0x10) && (dev->index <= 0x4a))
        ret = dev->regs[dev->index];
    else if ((addr == 0x23) && (dev->index == 0x57))
        ret = dev->reg_57h;
    else if (addr == 0x22)
        ret = dev->index;

    return ret;
}

static void
ali1429_close(void *priv)
{
    ali1429_t *dev = (ali1429_t *) priv;

    free(dev);
}

static void
ali1429_defaults(ali1429_t *dev)
{
    /* M1429 Defaults */
    dev->regs[0x10] = 0xf0;
    dev->regs[0x11] = 0xff;
    dev->regs[0x12] = 0x10;
    dev->regs[0x14] = 0x48;
    dev->regs[0x15] = 0x40;
    dev->regs[0x17] = 0x7a;
    dev->regs[0x1a] = 0x80;
    dev->regs[0x22] = 0x80;
    dev->regs[0x23] = 0x57;
    dev->regs[0x25] = 0xc0;
    dev->regs[0x27] = 0x30;

    /* M1429G Default Registers */
    if (GREEN) {
        dev->regs[0x31] = 0x88;
        dev->regs[0x32] = 0xc0;
        dev->regs[0x38] = 0xe5;
        dev->regs[0x40] = 0xe3;
        dev->regs[0x41] = 2;
        dev->regs[0x45] = 0x80;
    }
}

static void *
ali1429_init(const device_t *info)
{
    ali1429_t *dev = (ali1429_t *) calloc(1, sizeof(ali1429_t));

    dev->cfg_locked = 1;
    GREEN           = info->local;

    /* M1429 Ports:
                22h	Index Port
                23h	Data Port
    */
    io_sethandler(0x0022, 0x0002, ali1429_read, NULL, NULL, ali1429_write, NULL, NULL, dev);

    device_add(&port_92_device);

    ali1429_defaults(dev);

    return dev;
}

const device_t ali1429_device = {
    .name          = "ALi M1429",
    .internal_name = "ali1429",
    .flags         = 0,
    .local         = 0,
    .init          = ali1429_init,
    .close         = ali1429_close,
    .reset         = NULL,
    .available     = NULL,
    .speed_changed = NULL,
    .force_redraw  = NULL,
    .config        = NULL
};

const device_t ali1429g_device = {
    .name          = "ALi M1429G",
    .internal_name = "ali1429g",
    .flags         = 0,
    .local         = 1,
    .init          = ali1429_init,
    .close         = ali1429_close,
    .reset         = NULL,
    .available     = NULL,
    .speed_changed = NULL,
    .force_redraw  = NULL,
    .config        = NULL
};
