/* This can also serve as a sample PCI device. */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <wchar.h>
#include <86box/86box.h>
#include <86box/io.h>
#include <86box/pci.h>
#include <86box/pci_dummy.h>

static uint8_t pci_regs[256];

static bar_t pci_bar[2];

static uint8_t interrupt_on = 0x00;
static uint8_t card = 0;

static void pci_dummy_interrupt(int set)
{
        if (set)
	{
       	        pci_set_irq(card, pci_regs[0x3D]);
	}
        else
	{
       	        pci_clear_irq(card, pci_regs[0x3D]);
	}
}


static uint8_t pci_dummy_read(uint16_t Port, void *p)
{
	uint8_t ret = 0;

	switch(Port & 0x20)
	{
		case 0x00:
			return 0x1A;
		case 0x01:
			return 0x07;
		case 0x02:
			return 0x0B;
		case 0x03:
			return 0xAB;
		case 0x04:
			return pci_regs[0x3C];
		case 0x05:
			return pci_regs[0x3D];
		case 0x06:
			ret = interrupt_on;
			if (interrupt_on)
			{
				pci_dummy_interrupt(0);
				interrupt_on = 0;
			}
			return ret;
		default:
			return 0x00;
	}
}

static uint16_t pci_dummy_readw(uint16_t Port, void *p)
{
    return pci_dummy_read(Port, p);
}


static uint32_t pci_dummy_readl(uint16_t Port, void *p)
{
    return pci_dummy_read(Port, p);
}


static void pci_dummy_write(uint16_t Port, uint8_t Val, void *p)
{
	switch(Port & 0x20)
	{
		case 0x06:
			if (!interrupt_on)
			{
				interrupt_on = 1;
				pci_dummy_interrupt(1);
			}
			return;
		default:
			return;
	}
}

static void pci_dummy_writew(uint16_t Port, uint16_t Val, void *p)
{
	pci_dummy_write(Port, Val & 0xFF, p);
}

static void pci_dummy_writel(uint16_t Port, uint32_t Val, void *p)
{
	pci_dummy_write(Port, Val & 0xFF, p);
}


static void pci_dummy_io_remove(void)
{
	io_removehandler(pci_bar[0].addr, 0x0020, pci_dummy_read, pci_dummy_readw, pci_dummy_readl, pci_dummy_write, pci_dummy_writew, pci_dummy_writel, NULL);	
}

static void pci_dummy_io_set(void)
{
	io_sethandler(pci_bar[0].addr, 0x0020, pci_dummy_read, pci_dummy_readw, pci_dummy_readl, pci_dummy_write, pci_dummy_writew, pci_dummy_writel, NULL);	
}


static uint8_t pci_dummy_pci_read(int func, int addr, void *priv)
{
    pclog("AB0B:071A: PCI_Read(%d, %04x)\n", func, addr);

    switch(addr) {
	case 0x00:
		return 0x1A;
	case 0x01:
		return 0x07;
		break;

	case 0x02:
		return 0x0B;
	case 0x03:
		return 0xAB;

	case 0x04:			/* PCI_COMMAND_LO */
	case 0x05:			/* PCI_COMMAND_HI */
		return pci_regs[addr];

	case 0x06:			/* PCI_STATUS_LO */
	case 0x07:			/* PCI_STATUS_HI */
		return pci_regs[addr];

	case 0x08:
	case 0x09:
		return 0x00;

	case 0x0A:
		return pci_regs[addr];

	case 0x0B:
		return pci_regs[addr];

	case 0x10:			/* PCI_BAR 7:5 */
		return (pci_bar[0].addr_regs[0] & 0xe0) | 0x01;
	case 0x11:			/* PCI_BAR 15:8 */
		return pci_bar[0].addr_regs[1];
	case 0x12:			/* PCI_BAR 23:16 */
		return pci_bar[0].addr_regs[2];
	case 0x13:			/* PCI_BAR 31:24 */
		return pci_bar[0].addr_regs[3];

	case 0x2C:
		return 0x1A;
	case 0x2D:
		return 0x07;

	case 0x2E:
		return 0x0B;
	case 0x2F:
		return 0xAB;

	case 0x3C:			/* PCI_ILR */
		return pci_regs[addr];

	case 0x3D:			/* PCI_IPR */
		return pci_regs[addr];

	default:
		return 0x00;
    }
}

static void pci_dummy_pci_write(int func, int addr, uint8_t val, void *priv)
{
    uint8_t valxor;

    pclog("AB0B:071A: PCI_Write(%d, %04x, %02x)\n", func, addr, val);

    switch(addr) {
	case 0x04:			/* PCI_COMMAND_LO */
		valxor = (val & 0x03) ^ pci_regs[addr];
		if (valxor & PCI_COMMAND_IO)
		{
			pci_dummy_io_remove();
			if (((pci_bar[0].addr & 0xffe0) != 0) && (val & PCI_COMMAND_IO))
			{
				pci_dummy_io_set();
			}
		}
		pci_regs[addr] = val & 0x03;
		break;

	case 0x10:			/* PCI_BAR */
		val &= 0xe0;	/* 0xe0 acc to RTL DS */
		val |= 0x01;	/* re-enable IOIN bit */
		/*FALLTHROUGH*/

	case 0x11:			/* PCI_BAR */
	case 0x12:			/* PCI_BAR */
	case 0x13:			/* PCI_BAR */
		/* Remove old I/O. */
		pci_dummy_io_remove();

		/* Set new I/O as per PCI request. */
		pci_bar[0].addr_regs[addr & 3] = val;

		/* Then let's calculate the new I/O base. */
		pci_bar[0].addr &= 0xffe0;

		/* Log the new base. */
		pclog("AB0B:071A: PCI: new I/O base is %04X\n", pci_bar[0].addr);

		/* We're done, so get out of the here. */
		if (pci_regs[4] & PCI_COMMAND_IO)
		{
			if ((pci_bar[0].addr) != 0)
			{
				pci_dummy_io_set();
			}
		}
		break;

	case 0x3C:			/* PCI_ILR */
		pclog("AB0B:071A: IRQ now: %i\n", val);
		pci_regs[addr] = val;
		return;
    }
}


void pci_dummy_init(void)
{
	card = pci_add_card(PCI_ADD_NORMAL, pci_dummy_pci_read, pci_dummy_pci_write, NULL);

	pci_bar[0].addr_regs[0] = 0x01;
       	pci_regs[0x04] = 0x03;

       	pci_regs[0x3D] = PCI_INTD;
}