/*
 * 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.
 *
 *		Trident TVGA (8900D) emulation.
 *
 *
 *
 * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
 *		Miran Grca, <mgrca8@gmail.com>
 *
 *		Copyright 2008-2018 Sarah Walker.
 *		Copyright 2016-2018 Miran Grca.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <wchar.h>
#include <86box/86box.h>
#include <86box/io.h>
#include <86box/timer.h>
#include <86box/mem.h>
#include <86box/rom.h>
#include <86box/device.h>
#include <86box/video.h>
#include <86box/vid_svga.h>
#include <86box/vid_svga_render.h>

#define TVGA8900B_ID		0x03
#define TVGA9000B_ID		0x23
#define TVGA8900CLD_ID		0x33

#define ROM_TVGA_8900B		"roms/video/tvga/tvga8900b.vbi"
#define ROM_TVGA_8900CLD	"roms/video/tvga/trident.bin"
#define ROM_TVGA_9000B		"roms/video/tvga/tvga9000b.bin"

typedef struct tvga_t
{
        mem_mapping_t linear_mapping;
        mem_mapping_t accel_mapping;

        svga_t svga;

        rom_t bios_rom;
	uint8_t	card_id;

        uint8_t tvga_3d8, tvga_3d9;
        int oldmode;
        uint8_t oldctrl1;
        uint8_t oldctrl2, newctrl2;

        int vram_size;
        uint32_t vram_mask;
} tvga_t;

video_timings_t timing_tvga8900 = {VIDEO_ISA, 3,  3,  6,   8,  8, 12};
video_timings_t timing_tvga9000 = {VIDEO_ISA, 7,  7,  12,  7,  7, 12};

static uint8_t crtc_mask[0x40] =
{
        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
        0x7f, 0xff, 0x3f, 0x7f, 0xff, 0xff, 0xff, 0xff,
        0xff, 0xff, 0xff, 0xff, 0x7f, 0xff, 0xff, 0xef,
        0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
        0x7f, 0x00, 0x00, 0x2f, 0x00, 0x00, 0x00, 0x03,
        0x00, 0x13, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

static void tvga_recalcbanking(tvga_t *tvga);
void tvga_out(uint16_t addr, uint8_t val, void *p)
{
        tvga_t *tvga = (tvga_t *)p;
        svga_t *svga = &tvga->svga;

        uint8_t old;

        if (((addr&0xFFF0) == 0x3D0 || (addr&0xFFF0) == 0x3B0) && !(svga->miscout & 1)) addr ^= 0x60;

        switch (addr)
        {
                case 0x3C5:
                switch (svga->seqaddr & 0xf)
                {
                        case 0xB:
                        tvga->oldmode=1;
                        break;
                        case 0xC:
                        if (svga->seqregs[0xe] & 0x80)
                                svga->seqregs[0xc] = val;
                        break;
                        case 0xd:
                        if (tvga->oldmode)
                                tvga->oldctrl2 = val;
                        else
                        {
                                tvga->newctrl2 = val;
                                svga_recalctimings(svga);
                        }
                        break;
                        case 0xE:
                        if (tvga->oldmode)
                                tvga->oldctrl1 = val;
                        else
                        {
                                svga->seqregs[0xe] = val ^ 2;
                                tvga->tvga_3d8 = svga->seqregs[0xe] & 0xf;
                                tvga_recalcbanking(tvga);
                        }
                        return;
                }
                break;

                case 0x3C6: case 0x3C7: case 0x3C8: case 0x3C9:
		if (tvga->card_id != TVGA9000B_ID) {
			tkd8001_ramdac_out(addr, val, svga->ramdac, svga);
			return;
		}
		break;

                case 0x3CF:
                switch (svga->gdcaddr & 15)
                {
                        case 0x6:
                        old = svga->gdcreg[6];
                        svga_out(addr, val, svga);
                        if ((old & 0xc) != 0 && (val & 0xc) == 0)
                        {
                                /*override mask - TVGA supports linear 128k at A0000*/
                                svga->banked_mask = 0x1ffff;
                        }
                        return;
                        case 0xE:
                        svga->gdcreg[0xe] = val ^ 2;
                        tvga->tvga_3d9 = svga->gdcreg[0xe] & 0xf;
                        tvga_recalcbanking(tvga);
                        break;
                        case 0xF:
                        svga->gdcreg[0xf] = val;
                        tvga_recalcbanking(tvga);
                        break;
                }
                break;
                case 0x3D4:
		svga->crtcreg = val & 0x3f;
                return;
                case 0x3D5:
                if ((svga->crtcreg < 7) && (svga->crtc[0x11] & 0x80))
                        return;
                if ((svga->crtcreg == 7) && (svga->crtc[0x11] & 0x80))
                        val = (svga->crtc[7] & ~0x10) | (val & 0x10);
                old = svga->crtc[svga->crtcreg];
                val &= crtc_mask[svga->crtcreg];
                svga->crtc[svga->crtcreg] = val;
                if (old != val) {
                        if (svga->crtcreg < 0xe || svga->crtcreg > 0x10)
                        {
				if ((svga->crtcreg == 0xc) || (svga->crtcreg == 0xd)) {
                                	svga->fullchange = 3;
					svga->ma_latch = ((svga->crtc[0xc] << 8) | svga->crtc[0xd]) + ((svga->crtc[8] & 0x60) >> 5);
				} else {
					svga->fullchange = changeframecount;
	                                svga_recalctimings(svga);
				}
                        }
                }
                switch (svga->crtcreg) {
                        case 0x1e:
                        svga->vram_display_mask = (val & 0x80) ? tvga->vram_mask : 0x3ffff;
                        break;
                }
                return;
                case 0x3D8:
                if (svga->gdcreg[0xf] & 4) {
                        tvga->tvga_3d8 = val;
                        tvga_recalcbanking(tvga);
                }
                return;
                case 0x3D9:
                if (svga->gdcreg[0xf] & 4) {
                        tvga->tvga_3d9 = val;
                        tvga_recalcbanking(tvga);
                }
                return;
                case 0x3DB:
                if (tvga->card_id != TVGA9000B_ID) {
                        /*3db appears to be a 4 bit clock select register on 8900D*/
                        svga->miscout = (svga->miscout & ~0x0c) | ((val & 3) << 2);
                        tvga->newctrl2 = (tvga->newctrl2 & ~0x01) | ((val & 4) >> 2);
                        tvga->oldctrl1 = (tvga->oldctrl1 & ~0x10) | ((val & 8) << 1);
                        svga_recalctimings(svga);
                }
                break;
        }
        svga_out(addr, val, svga);
}

uint8_t tvga_in(uint16_t addr, void *p)
{
        tvga_t *tvga = (tvga_t *)p;
        svga_t *svga = &tvga->svga;

        if (((addr&0xFFF0) == 0x3D0 || (addr&0xFFF0) == 0x3B0) && !(svga->miscout & 1)) addr ^= 0x60;

        switch (addr)
        {
                case 0x3C5:
                if ((svga->seqaddr & 0xf) == 0xb)
                {
                        tvga->oldmode = 0;
                        return tvga->card_id; /*Must be at least a TVGA8900*/
                }
                if ((svga->seqaddr & 0xf) == 0xd)
                {
                        if (tvga->oldmode) return tvga->oldctrl2;
                        return tvga->newctrl2;
                }
                if ((svga->seqaddr & 0xf) == 0xe)
                {
                        if (tvga->oldmode)
                                return tvga->oldctrl1;
                }
                break;
                case 0x3C6: case 0x3C7: case 0x3C8: case 0x3C9:
                if (tvga->card_id != TVGA9000B_ID) {
			return tkd8001_ramdac_in(addr, svga->ramdac, svga);
		}
		break;
                case 0x3D4:
                return svga->crtcreg;
                case 0x3D5:
                if (svga->crtcreg > 0x18 && svga->crtcreg < 0x1e)
                        return 0xff;
                return svga->crtc[svga->crtcreg];
                case 0x3d8:
		return tvga->tvga_3d8;
		case 0x3d9:
		return tvga->tvga_3d9;
        }
        return svga_in(addr, svga);
}

static void tvga_recalcbanking(tvga_t *tvga)
{
        svga_t *svga = &tvga->svga;

        svga->write_bank = (tvga->tvga_3d8 & 0x1f) * 65536;

        if (svga->gdcreg[0xf] & 1)
                svga->read_bank = (tvga->tvga_3d9 & 0x1f) * 65536;
        else
                svga->read_bank = svga->write_bank;
}

void tvga_recalctimings(svga_t *svga)
{
        tvga_t *tvga = (tvga_t *)svga->p;
	int clksel;
	int high_res_256 = 0;

        if (!svga->rowoffset) svga->rowoffset = 0x100; /*This is the only sensible way I can see this being handled,
                                                         given that TVGA8900D has no overflow bits.
                                                         Some sort of overflow is required for 320x200x24 and 1024x768x16*/
        if (svga->crtc[0x29] & 0x10)
                svga->rowoffset += 0x100;

        if (svga->bpp == 24)
                svga->hdisp = (svga->crtc[1] + 1) * 8;

	if ((svga->crtc[0x1e] & 0xA0) == 0xA0) svga->ma_latch |= 0x10000;
	if ((svga->crtc[0x27] & 0x01) == 0x01) svga->ma_latch |= 0x20000;
	if ((svga->crtc[0x27] & 0x02) == 0x02) svga->ma_latch |= 0x40000;

        if (tvga->oldctrl2 & 0x10)
        {
                svga->rowoffset <<= 1;
                svga->ma_latch <<= 1;
        }

        if (svga->gdcreg[0xf] & 0x08)
        {
                svga->htotal *= 2;
                svga->hdisp *= 2;
                svga->hdisp_time *= 2;
        }

	svga->interlace = (svga->crtc[0x1e] & 4);

        if (svga->interlace)
                svga->rowoffset >>= 1;

	if (tvga->card_id == TVGA8900CLD_ID)
		clksel = ((svga->miscout >> 2) & 3) | ((tvga->newctrl2 & 0x01) << 2) | ((tvga->oldctrl1 & 0x10) >> 1);
	else
		clksel = ((svga->miscout >> 2) & 3) | ((tvga->newctrl2 & 0x01) << 2) | ((tvga->newctrl2 & 0x40) >> 3);

        switch (clksel) {
                case 0x2: svga->clock = (cpuclock * (double)(1ull << 32)) / 44900000.0; break;
                case 0x3: svga->clock = (cpuclock * (double)(1ull << 32)) / 36000000.0; break;
                case 0x4: svga->clock = (cpuclock * (double)(1ull << 32)) / 57272000.0; break;
                case 0x5: svga->clock = (cpuclock * (double)(1ull << 32)) / 65000000.0; break;
                case 0x6: svga->clock = (cpuclock * (double)(1ull << 32)) / 50350000.0; break;
                case 0x7: svga->clock = (cpuclock * (double)(1ull << 32)) / 40000000.0; break;
                case 0x8: svga->clock = (cpuclock * (double)(1ull << 32)) / 88000000.0; break;
                case 0x9: svga->clock = (cpuclock * (double)(1ull << 32)) / 98000000.0; break;
                case 0xa: svga->clock = (cpuclock * (double)(1ull << 32)) / 118800000.0; break;
                case 0xb: svga->clock = (cpuclock * (double)(1ull << 32)) / 108000000.0; break;
                case 0xc: svga->clock = (cpuclock * (double)(1ull << 32)) / 72000000.0; break;
                case 0xd: svga->clock = (cpuclock * (double)(1ull << 32)) / 77000000.0; break;
                case 0xe: svga->clock = (cpuclock * (double)(1ull << 32)) / 80000000.0; break;
                case 0xf: svga->clock = (cpuclock * (double)(1ull << 32)) / 75000000.0; break;
        }

	if (tvga->card_id != TVGA8900CLD_ID) {
                /*TVGA9000 doesn't seem to have support for a 'high res' 256 colour mode
                  (without the VGA pixel doubling). Instead it implements these modes by
                  doubling the horizontal pixel count and pixel clock. Hence we use a
                  basic heuristic to detect this*/
                if (svga->interlace)
                        high_res_256 = (svga->htotal * 8) > (svga->vtotal * 4);
                else
                        high_res_256 = (svga->htotal * 8) > (svga->vtotal * 2);
	}

        if ((tvga->oldctrl2 & 0x10) || high_res_256)
        {
                if (high_res_256)
                        svga->hdisp /= 2;
                switch (svga->bpp)
                {
                        case 8:
                        svga->render = svga_render_8bpp_highres;
                        break;
                        case 15:
                        svga->render = svga_render_15bpp_highres;
                        svga->hdisp /= 2;
                        break;
                        case 16:
                        svga->render = svga_render_16bpp_highres;
                        svga->hdisp /= 2;
                        break;
                        case 24:
                        svga->render = svga_render_24bpp_highres;
                        svga->hdisp /= 3;
                        break;
                }
                svga->lowres = 0;
        }
}


static void *tvga_init(const device_t *info)
{
	const char *bios_fn;
        tvga_t *tvga = malloc(sizeof(tvga_t));
        memset(tvga, 0, sizeof(tvga_t));

        if (info->local == TVGA9000B_ID) {
		video_inform(VIDEO_FLAG_TYPE_SPECIAL, &timing_tvga9000);
		tvga->vram_size = 512 << 10;
	} else {
		video_inform(VIDEO_FLAG_TYPE_SPECIAL, &timing_tvga8900);
		tvga->vram_size = device_get_config_int("memory") << 10;
        }

	tvga->vram_mask = tvga->vram_size - 1;

	tvga->card_id = info->local;

	switch (info->local)
	{
		case TVGA8900B_ID:
			bios_fn = ROM_TVGA_8900B;
			break;
		case TVGA8900CLD_ID:
			bios_fn = ROM_TVGA_8900CLD;
			break;
		case TVGA9000B_ID:
			bios_fn = ROM_TVGA_9000B;
			break;
		default:
			free(tvga);
			return NULL;
	}

        rom_init(&tvga->bios_rom, (char *) bios_fn, 0xc0000, 0x8000, 0x7fff, 0, MEM_MAPPING_EXTERNAL);

        svga_init(info, &tvga->svga, tvga, tvga->vram_size,
                   tvga_recalctimings,
                   tvga_in, tvga_out,
                   NULL,
                   NULL);

	if (info->local != TVGA9000B_ID)
		tvga->svga.ramdac = device_add(&tkd8001_ramdac_device);

        io_sethandler(0x03c0, 0x0020, tvga_in, NULL, NULL, tvga_out, NULL, NULL, tvga);

        return tvga;
}

static int tvga8900b_available(void)
{
        return rom_present(ROM_TVGA_8900B);
}

static int tvga8900d_available(void)
{
        return rom_present(ROM_TVGA_8900CLD);
}

static int tvga9000b_available(void)
{
        return rom_present(ROM_TVGA_9000B);
}

void tvga_close(void *p)
{
        tvga_t *tvga = (tvga_t *)p;

        svga_close(&tvga->svga);

        free(tvga);
}

void tvga_speed_changed(void *p)
{
        tvga_t *tvga = (tvga_t *)p;

        svga_recalctimings(&tvga->svga);
}

void tvga_force_redraw(void *p)
{
        tvga_t *tvga = (tvga_t *)p;

        tvga->svga.fullchange = changeframecount;
}

static const device_config_t tvga_config[] =
{
// clang-format off
    {
        "memory", "Memory size", CONFIG_SELECTION, "", 1024, "", { 0 },
        {
            { "256 kB", 256 },
            { "512 kB", 512 },
            { "1 MB", 1024 },
            /*Chip supports 2mb, but drivers are buggy*/
            { "" }
        }
    },
    { "", "", -1 }
// clang-format off
};

const device_t tvga8900b_device =
{
        "Trident TVGA 8900B",
        "tvga8900b",
        DEVICE_ISA,
    TVGA8900B_ID,
        tvga_init,
        tvga_close,
    NULL,
        { tvga8900b_available },
        tvga_speed_changed,
        tvga_force_redraw,
        tvga_config
};

const device_t tvga8900d_device =
{
        "Trident TVGA 8900D",
        "tvga8900d",
        DEVICE_ISA,
    TVGA8900CLD_ID,
        tvga_init,
        tvga_close,
    NULL,
        { tvga8900d_available },
        tvga_speed_changed,
        tvga_force_redraw,
        tvga_config
};

const device_t tvga9000b_device =
{
        "Trident TVGA 9000B",
        "tvga9000b",
        DEVICE_ISA,
    TVGA9000B_ID,
        tvga_init,
        tvga_close,
    NULL,
        { tvga9000b_available },
        tvga_speed_changed,
        tvga_force_redraw,
        NULL
};
