/*
  MSP430 Emulator
  Copyright (C) 2020 Rudolf Geosits (rgeosits@live.esu.edu)

  "MSP430 Emulator" is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  "MSP430 Emulator" is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program. If not, see <https://www.gnu.org/licenses/>.
*/

#include "port1.h"

/* Cheat Sheet:
 *  PxIN :  0 = LOW input, 1 = HIGH input
 *  PxOUT:  0 = LOW output, 1 = HIGH output
 *  PxDIR:  0 = INPUT, 1 = OUTPUT
 *  PxREN:  0 = Pull Up/Down DISABLED, 1 = Pull Up/Down ENABLED
 *
 *  PxSEL2 | PxSEL | Explaination
 *       0 |     0 | I/O function selected 
 *       0 |     1 | Primary Peripheral module function selected
 *       1 |     0 | Reserved ?
 *       1 |     1 | Secondary Peripheral module function selected
 *  [NOTE: P1 and P2 port pin INTs are disabled when PxSEL = 1]
 *
 *  PxIFG:  0 = No interrupt pending, 1 = Interrupt Pending
 *  PxIES:  PxIFG set with a [0 = LOW-HIGH, 1 = HIGH-LOW] transition 
 *  PxIE :  0 = interrupt disabled, 1 = interrupt enabled
 */

void handle_port_1 (Emulator *emu)
{
    Cpu *cpu = emu->cpu;
    Port_1 *p = cpu->p1;

    //////////////////// P1.0 ////////////////////////

    // Check Direction
    if (*p->DIR & 0x01) {
        p->DIR_0 = true;           // Set P1DIR.0 flag
        if (*p->OUT & 0x01)        // Check OUTPUT
            p->OUT_0 = true;       // Set P1OUT.0 flag
        else
            p->OUT_0 = false;      // Reset P1OUT.0 flag
    }
    // Check INPUT 
    else {
        p->DIR_0 = false;
    }
    
    /// Check if Interrupt Enabled for pin 
    if (*p->IE & 0x01)
    {         
        p->IE_0 = true;

        // Check For Interrupt Pending 
        if (*p->IFG & 0x01)
        {    
            // Set p->IFG.0 flag indicating INT 
            p->IFG_0 = true;
        }
        else
        {
            p->IFG_0 = false;
        }
    }
    else
    {
        p->IE_0 = false;
    }    
    
    // Check primary select
    if (*p->SEL & 0x01) {
        if (p->SEL_0 == false) {
            puts("P1_SEL_0 = 1");
        }
        
        p->SEL_0 = true;
    }
    else {
        if (p->SEL_0 == true) {
            puts("P1_SEL_0 = 0");
        }

        p->SEL_0 = false;
    }

    // Check secondary select
    if (*p->SEL2 & 0x01) {
        if (p->SEL2_0 == false) {
            puts("P1_SEL2_0 = 1");
        }
        
        p->SEL2_0 = true;
    }
    else {
        if (p->SEL2_0 == true) {
            puts("P1_SEL2_0 = 0");
        }

        p->SEL2_0 = false;        
    }

    //////////////////// P1.1 ////////////////////////

    // Check Direction and IN/OUT
    if (*p->DIR & 0x02) {
        p->DIR_1 = true;
        if (*p->OUT & 0x02) {
            p->OUT_1 = true;
        }
        else {
            p->OUT_1 = false;
        }
    }
    else {
        p->DIR_1 = false;
    }

    // Check Interrupts
    if (*p->IE & 0x02) {
        p->IE_1 = true;

        if (*p->IFG & 0x02) {
            p->IFG_1 = true;
        }
        else {
            p->IFG_1 = false;
        }
    }
    else {
        p->IE_1 = false;
    }

    // Check primary select
    if (*p->SEL & 0x02) {
        if (p->SEL_1 == false) {
            puts("P1_SEL_1 = 1");
        }

        p->SEL_1 = true;
    }
    else {
        if (p->SEL_1 == true) {
            puts("P1_SEL_1 = 0");
        }

        p->SEL_1 = false;
    }

    // Check secondary select
    if (*p->SEL2 & 0x02) {
        if (p->SEL2_1 == false) {
            p->SEL2_1 = true;
            puts("P1_SEL2_1 = 1");
        }
    }
    else {
        if (p->SEL2_1 == true) {
            p->SEL2_1 = false;        
            puts("P1_SEL2_1 = 0");
        }
    }

    //////////////////// P1.2 ////////////////////////

    if (*p->DIR & 0x04)
    {
        p->DIR_2 = true;

        if (*p->OUT & 0x04)
        {
            p->OUT_2 = true;
        }
        else
        {
            p->OUT_2 = false;
        }
    }
    else
    {
        p->DIR_2 = false;
    }

    if (*p->IE & 0x04)
    {
        p->IE_2 = true;

        if (*p->IFG & 0x04)
        {
            p->IFG_2 = true;
        }
        else
        {
            p->IFG_2 = false;
        }
    }
    else
    {
        p->IE_2 = false;
    }

    // Check primary select
    if (*p->SEL & 0x04)
    {
        if (p->SEL_2 == false) 
        {
            puts("P1_SEL_2 = 1");
        }
        
        p->SEL_2 = true;
    }
    else
    {
        if (p->SEL_2 == true)
        {
            puts("P1_SEL_2 = 0");
        }

        p->SEL_2 = false;
    }

    // Check secondary select
    if (*p->SEL2 & 0x04) {
        if (p->SEL2_2 == false) {
            puts("P1_SEL2_2 = 1");
        }
        
        p->SEL2_2 = true;
    }
    else {
        if (p->SEL2_2 == true) {
            puts("P1_SEL2_2 = 0");
        }

        p->SEL2_2 = false;        
    }

    ////////////////////////////////////////////////

    // Handler P1.3 
    if (*p->DIR & 0x08) {
        p->DIR_3 = true;
        if (*p->OUT & 0x08) {
            p->OUT_3 = true;
        }
        else {
            p->OUT_3 = false;
        }
    }
    else {
        p->DIR_3 = false;
    }

    if (*p->IE & 0x08) {
        p->IE_3 = true;

        if (*p->IFG & 0x08) {
            p->IFG_3 = true;
        }
        else {
            p->IFG_3 = false;
        }
    }
    else {
        p->IE_3 = false;
    }

    ///////////////////////////////////////////////////////////////

    // Handler P1.4 
    if (*p->DIR & 0x10) {
        p->DIR_4 = true;
        if (*p->OUT & 0x10) {
            p->OUT_4 = true;
        }
        else {
            p->OUT_4 = false;
        }
    }
    else {
        p->DIR_4 = false;
    }

    if (*p->IE & 0x10) {
        p->IE_4 = true;

        if (*p->IFG & 0x10) {
            p->IFG_4 = true;
        }
        else {
            p->IFG_4 = false;
        }
    }
    else {
        p->IE_4 = false;
    }

    /////////////////////////////////////////////////

    // Handler P1.5 
    if (*p->DIR & 0x20) {
        p->DIR_5 = true;
        if (*p->OUT & 0x20) {
            p->OUT_5 = true;
        }
        else {
            p->OUT_5 = false;
        }
    }
    else {
        p->DIR_5 = false;
    }

    if (*p->IE & 0x20) {
        p->IE_5 = true;

        if (*p->IFG & 0x20) {
            p->IFG_5 = true;
        }
        else {
            p->IFG_5 = false;
        }
    }
    else {
        p->IE_5 = false;
    }

    ////////////////////////////////////////////////////

    // Handler P1.6 
    if (*p->DIR & 0x40)
    {
        p->DIR_6 = true;
        if (*p->OUT & 0x40)
        {
            p->OUT_6 = true;
        }
        else
        {
            p->OUT_6 = false;
        }
    }
    else
    {
        p->DIR_6 = false;
    }

    if (*p->IE & 0x40)
    {
        p->IE_6 = true;

        if (*p->IFG & 0x40)
        {
            p->IFG_6 = true;
        }
        else
        {
            p->IFG_6 = false;
        }
    }
    else
    {
        p->IE_6 = false;
    }

    ////////////////////////////////////////////////////

    // Handler P1.7 
    if (*p->DIR & 0x80) {
        p->DIR_7 = true;
        if (*p->OUT & 0x80) {
            p->OUT_7 = true;
        }
        else {
            p->OUT_7 = false;
        }
    }
    else {
        p->DIR_7 = false;
    }

    if (*p->IE & 0x80) {
        p->IE_7 = true;

        if (*p->IFG & 0x80) {
            p->IFG_7 = true;
        }
        else {
            p->IFG_7 = false;
        }
    }
    else {
        p->IE_7 = false;
    }
}

void setup_port_1 (Emulator *emu)
{
    Cpu *cpu = emu->cpu;
    Port_1 *p = cpu->p1;
  
    static const uint16_t IN_VLOC   = 0x20;   // Input
    static const uint16_t OUT_VLOC  = 0x21;   // Output
    static const uint16_t DIR_VLOC  = 0x22;   // Direction
    static const uint16_t IFG_VLOC  = 0x23;   // Interrupt flag
    static const uint16_t IES_VLOC  = 0x24;   // Interrupt Edge Select
    static const uint16_t IE_VLOC   = 0x25;   // Interrupt Enable
    static const uint16_t SEL_VLOC  = 0x26;   // Select
    static const uint16_t SEL2_VLOC = 0x41;   // Select 2
    static const uint16_t REN_VLOC  = 0x27;   // Resistor Enable
  
    *(p->IN   = (uint8_t *) get_addr_ptr(IN_VLOC))   = 0;
    *(p->OUT  = (uint8_t *) get_addr_ptr(OUT_VLOC))  = 0;
    *(p->DIR  = (uint8_t *) get_addr_ptr(DIR_VLOC))  = 0;
    *(p->IFG  = (uint8_t *) get_addr_ptr(IFG_VLOC))  = 0;
    *(p->IES  = (uint8_t *) get_addr_ptr(IES_VLOC))  = 0;
    *(p->IE   = (uint8_t *) get_addr_ptr(IE_VLOC))   = 0;
    *(p->SEL  = (uint8_t *) get_addr_ptr(SEL_VLOC))  = 0;
    *(p->SEL2 = (uint8_t *) get_addr_ptr(SEL2_VLOC)) = 0;
    *(p->REN  = (uint8_t *) get_addr_ptr(REN_VLOC))  = 0;

  
    p->DIR_0 = false; p->OUT_0 = false; p->IFG_0 = false; 
    p->IE_0 = false; p->SEL_0 = false; p->SEL2_0 = false;
    
    p->DIR_1 = false; p->OUT_1 = false; p->IFG_1 = false; 
    p->IE_1 = false; p->SEL_1 = false; p->SEL2_1 = false;
    
    p->DIR_2 = false; p->OUT_2 = false; p->IFG_2 = false; 
    p->IE_2 = false; p->SEL_2 = false; p->SEL2_2 = false;
    
    p->DIR_3 = false; p->OUT_3 = false; p->IFG_3 = false; 
    p->IE_3 = false; p->SEL_3 = false; p->SEL2_3 = false;
    
    p->DIR_4 = false; p->OUT_4 = false; p->IFG_4 = false; 
    p->IE_4 = false; p->SEL_4 = false; p->SEL2_4 = false;
    
    p->DIR_5 = false; p->OUT_5 = false; p->IFG_5 = false; 
    p->IE_5 = false; p->SEL_5 = false; p->SEL2_5 = false;
    
    p->DIR_6 = false; p->OUT_6 = false; p->IFG_6 = false; 
    p->IE_6 = false; p->SEL_6 = false; p->SEL2_6 = false;
    
    p->DIR_7 = false; p->OUT_7 = false; p->IFG_7 = false; 
    p->IE_7 = false; p->SEL_7 = false; p->SEL2_7 = false;
}

/* POWER UP CLEAR (PUC)      
 *
 * A PUC is always generated when a POR is generated, but a POR is not
 * generated by a PUC. The following events trigger a PUC:  
 *                                                
 * A POR signal                             
 * Watchdog timer expiration when in watchdog mode only
 * Watchdog timer security key violation          
 * A Flash memory security key violation        
 * A CPU instruct fetch from the peripheral address range 0h to 01FFh

void power_up_clear () {
  *P1OUT = *P1DIR = *P1IFG = *P1IE = *P1SEL = *P1SEL2 = *P1REN = 0;
}
 */