//DingusPPC - Prototype 5bf2
//Written by divingkatae
//(c)2018-20 (theweirdo)
//Please ask for permission
//if you want to distribute this.
//(divingkatae#1017 on Discord)

//Functionality for the MPC106

#include <iostream>
#include <cstring>
#include <cinttypes>
#include "viacuda.h"
#include "mpc106.h"
#include "ppcemumain.h"
#include "ppcmemory.h"

bool mpc106_address_map;

uint32_t mpc106_address;  // For fe000000 - fe00ffff
uint32_t mpc_config_addr; // Device No. and Reg No. included
uint32_t mpc_config_dat;  // Value to write to the device

uint32_t mpc106_write_word;
uint32_t mpc106_read_word;
uint16_t mpc106_write_half;
uint16_t mpc106_read_half;
uint8_t mpc106_write_byte;
uint8_t mpc106_read_byte;

void mpc106_init(){
    mpc_config_addr = 0;
    mpc_config_dat = 0;

    //Initialize Vendor & Device IDs
    machine_fexxxx_mem[0x00] = 0x57;
    machine_fexxxx_mem[0x01] = 0x10;

    machine_fexxxx_mem[0x02] = 0x02;

    //PCI command + status
    machine_fexxxx_mem[0x04] = 0x06;
    machine_fexxxx_mem[0x06] = 0x80;

    machine_fexxxx_mem[0x0B] = 0x06;
    machine_fexxxx_mem[0x0C] = 0x08;

    machine_fexxxx_mem[0x73] = 0xCD;

    machine_fexxxx_mem[0xA8] = 0x10;
    machine_fexxxx_mem[0xA9] = 0x00;
    machine_fexxxx_mem[0xAA] = 0x00;
    machine_fexxxx_mem[0xAB] = 0xFF;

    machine_fexxxx_mem[0xAC] = 0x0C;
    machine_fexxxx_mem[0xAD] = 0x06;
    machine_fexxxx_mem[0xAE] = 0x0C;
    machine_fexxxx_mem[0xAF] = 0x00;

    machine_fexxxx_mem[0xBA] = 0x04;

    machine_fexxxx_mem[0xAC] = 0x0C;
    machine_fexxxx_mem[0xAD] = 0x06;
    machine_fexxxx_mem[0xAE] = 0x0C;
    machine_fexxxx_mem[0xAF] = 0x00;

    machine_fexxxx_mem[0xAC] = 0x0C;
    machine_fexxxx_mem[0xAD] = 0x06;
    machine_fexxxx_mem[0xAE] = 0x0C;
    machine_fexxxx_mem[0xAF] = 0x00;

    machine_fexxxx_mem[0xAC] = 0x0C;
    machine_fexxxx_mem[0xAD] = 0x06;
    machine_fexxxx_mem[0xAE] = 0x0C;
    machine_fexxxx_mem[0xAF] = 0x00;

    machine_fexxxx_mem[0xF0] = 0x00;
    machine_fexxxx_mem[0xF1] = 0x00;
    machine_fexxxx_mem[0xF2] = 0x02;
    machine_fexxxx_mem[0xF3] = 0xFF;

    machine_fexxxx_mem[0xF4] = 0x03;
    machine_fexxxx_mem[0xF5] = 0x00;
    machine_fexxxx_mem[0xF6] = 0x00;
    machine_fexxxx_mem[0xF7] = 0x00;

    machine_fexxxx_mem[0xFC] = 0x00;
    machine_fexxxx_mem[0xFD] = 0x00;
    machine_fexxxx_mem[0xFE] = 0x10;
    machine_fexxxx_mem[0xFF] = 0x00;
}

uint32_t mpc106_write_device(uint32_t device_addr, uint32_t insert_to_device, uint8_t bit_length){
    //Write to the specified device - Invoked when a write is made to 0xFEExxxxx.
    //device_addr is what's stored in 0xFEC00CF8 (The MPG106/Grackle's CONFIG_ADDR Register).

    uint32_t reg_num  = (device_addr & 0x07FC) >> 2;
    uint32_t dev_num  = (device_addr & 0xF800) >> 11;

    switch(dev_num){
    case 0:
        //Device 0 is reserved to the grackle by default
        mpc106_address = reg_num;
        mpc106_write(insert_to_device);
        break;
    case 16:
    case 17:
        via_cuda_address = (reg_num << 9) + (dev_num << 12) + 0x3000000;
        via_write_byte = (uint8_t)insert_to_device;
        via_cuda_write();
        break;
    }

    return 0;
}

uint32_t mpc106_read_device(uint32_t device_addr, uint8_t bit_length){
    //Read to the specified device - Invoked when a read is made to 0xFEExxxxx.
    //device_addr is what's stored in 0xFEC00CF8 (The MPG106/Grackle's CONFIG_ADDR Register).

    uint32_t reg_num = (device_addr & 0x07FC) >> 2;
    uint32_t dev_num = (device_addr & 0xF800) >> 11;

    uint32_t grab_value = 0;

    switch(dev_num){
    case 0:
        //Device 0 is reserved to the grackle by default
        mpc106_address = reg_num;
        mpc106_read();
        grab_value = mpc106_read_word;
        break;
    case 16:
    case 17:
        via_cuda_address = (reg_num << 8) + (dev_num << 12) + 0x3000000;
        via_cuda_read();
        grab_value = (uint32_t)via_read_byte;
        break;
    }

    return grab_value;
}

void mpc106_read(){

    uint8_t read_length = 4;

    switch (mpc106_address){
    case 0x8:
    case 0x9:
    case 0xA:
    case 0xB:
    case 0xC:
    case 0xD:
    case 0xE:
    case 0xF:
    case 0x3C:
    case 0x3D:
    case 0x3E:
    case 0x3F:
    case 0x72:
    case 0x73:
    case 0xA0:
    case 0xA3:
        read_length = 1;
        break;
    case 0x0:
    case 0x2:
    case 0x4:
    case 0x6:
    case 0x70:
        read_length = 2;
        break;
    case 0x80:
    case 0x84:
    case 0x88:
    case 0x8C:
    case 0x90:
    case 0x94:
    case 0x98:
    case 0x9C:
    case 0xF0:
    case 0xF4:
    case 0xF8:
    case 0xFC:
        read_length = 4;
    default: //Avoid writing into reserved areas
        read_length = 0;
    }

    switch(read_length){
        case 1:
            mpc106_read_word |= (grab_macmem_ptr[mpc106_address]);
            break;
        case 2:
            mpc106_read_word |= (grab_macmem_ptr[mpc106_address++]);
            mpc106_read_word |= (grab_macmem_ptr[mpc106_address]) << 8;
            break;
        case 4:
            mpc106_read_word |= (grab_macmem_ptr[mpc106_address++]);
            mpc106_read_word |= (grab_macmem_ptr[mpc106_address++]) << 8;
            mpc106_read_word |= (grab_macmem_ptr[mpc106_address++]) << 16;
            mpc106_read_word |= (grab_macmem_ptr[mpc106_address]) << 24;
            break;
    }

}

void mpc106_write(uint32_t write_word){

    uint8_t write_length = 4;

    switch (mpc106_address){
    case 0x70:
    case 0x72:
    case 0x73:
    case 0xA0:
    case 0xA3:
        write_length = 1;
        break;
    case 0x4:
    case 0x6:
        write_length = 2;
        break;
    case 0x80:
    case 0x84:
    case 0x88:
    case 0x8C:
    case 0x90:
    case 0x94:
    case 0x98:
    case 0x9C:
    case 0xF0:
    case 0xF4:
    case 0xF8:
    case 0xFC:
        write_length = 4;
    default: //Avoid writing into reserved areas
        write_length = 0;
    }

    switch(write_length){
        case 1:
            grab_macmem_ptr[mpc106_address] |= (uint8_t)((mpc106_read_word) & 0xFF);
            break;
        case 2:
            grab_macmem_ptr[mpc106_address++] |= (uint8_t)((mpc106_read_word) & 0xFF);
            grab_macmem_ptr[mpc106_address] |= (uint8_t)((mpc106_read_word >> 8) & 0xFF);
            break;
        case 4:
            if ((mpc106_address == 0x88) | (mpc106_address == 0x8C) | (mpc106_address == 0x98) | (mpc106_address == 0x9C)){
                grab_macmem_ptr[mpc106_address++] |= (uint8_t)((mpc106_read_word) & 0x03);
                grab_macmem_ptr[mpc106_address++] |= (uint8_t)((mpc106_read_word >> 8) & 0x03);
                grab_macmem_ptr[mpc106_address++] |= (uint8_t)((mpc106_read_word >> 16) & 0x03);
                grab_macmem_ptr[mpc106_address] |= (uint8_t)((mpc106_read_word >> 24) & 0x03);
                break;
            }
            else{
                grab_macmem_ptr[mpc106_address++] |= (uint8_t)((mpc106_read_word) & 0xFF);
                grab_macmem_ptr[mpc106_address++] |= (uint8_t)((mpc106_read_word >> 8) & 0xFF);
                grab_macmem_ptr[mpc106_address++] |= (uint8_t)((mpc106_read_word >> 16) & 0xFF);
                grab_macmem_ptr[mpc106_address] |= (uint8_t)((mpc106_read_word >> 24) & 0xFF);
                break;
            }
    }
}