ps/2 for rosco68k

kmain.c

/*
 * Copyright (c) 2020 You (you@youremail.com)
 */
 // Some function copied from dua_gpi_spi.h
 // Part of the PS/2 algorithm borrowed from http://www.technoblogy.com/show?1GYR

#include <stdio.h>
#include <machine.h>


// HI/LO refer to physical pin state, these ports are active
// low, so they appear reversed here...
static volatile uint8_t *DUART_OUTLOPORT = (uint8_t*)DUART_W_OPR_SETCMD;
static volatile uint8_t *DUART_OUTHIPORT = (uint8_t*)DUART_W_OPR_RESETCMD;
static volatile uint8_t *DUART_INPUTPORT = (uint8_t*)DUART_R_INPUTPORT;

static bool clockOld = true;

static uint16_t ScanCode = 0;
static uint16_t ScanBit = 1;

static uint16_t Break = 0;
static uint16_t Modifier = 0;
static uint16_t Shift = 0;

static uint16_t currentChar = 0;

static uint32_t oldTimer = 0;


#define  KBD_DATA 4
#define  KBD_CLOCK 5

#define  KBD_DATA_PIN (1 << KBD_DATA)
#define  KBD_CLOCK_PIN (1 << KBD_CLOCK)

#define KeymapSize 132
static const char Keymap[] = 
// Without shift
"             \011`      q1   zsaw2  cxde43   vftr5  nbhgy6   mju78  ,kio09"
"  ./l;p-   \' [=    \015] \\        \010  1 47   0.2568\033  +3-*9      "
// With shift
"             \011~      Q!   ZSAW@  CXDE$#   VFTR%  NBHGY^   MJU&*  <KIO)("
"  >?L:P_   \" {+    \015} |        \010  1 47   0.2568\033  +3-*9       ";

static void digitalWrite(uint8_t pinmask, bool value) {
    if (value) {
        *DUART_OUTHIPORT = pinmask;
    } else {
        *DUART_OUTLOPORT = pinmask;
    }
}

static bool digitalRead(uint8_t pinmask) {
    return ((*DUART_INPUTPORT) & pinmask);
}


static void turnOnRedLed() {

    // Turn on Red LED
    *DUART_OUTLOPORT = 8;
}

static void turnOffRedLed() {

    // Turn off Red LED
    *DUART_OUTHIPORT = 8;
}

static void handleNewDataBit(bool dataBit) {
    uint16_t s;
    
    
    //Timeout during recieving one byte
    if (oldTimer + 10 < _TIMER_100HZ && ScanBit != 1) {
        printf("timeout receiving the remaining bits 0x%x, ScanCode 0x%x-> reseting!\n", ScanBit, ScanCode);
        ScanCode = 0;
        ScanBit = 1;
    }
    oldTimer = _TIMER_100HZ;
    
    
    if (dataBit) {
        ScanCode = ScanCode | ScanBit;
    }
    ScanBit = ScanBit << 1;
    
    if (ScanBit != 0x800) {
        return;
    }
    // Process scan code
    if ((ScanCode & 0x401) != 0x400) { // Invalid start/stop bit
        printf("invalid start/stop bit! ScanCode: 0x%x\n", ScanCode);
        ScanCode = 0;
        ScanBit = 1;
        return; 
    }
    s = (ScanCode & 0x1FE) >> 1;
    ScanCode = 0;
    ScanBit = 1;
    if (s == 0xAA) { // BAT completion code
        return; 
    }
    if (s == 0xF0) {
        Break = 1;
        return;
    }
    if (s == 0xE0) {
        Modifier = 1;
        return;
    }
    if (Break) {
        if ((s == 0x12) || (s == 0x59)) {
            Shift = 0;
        }
        Break = 0;
        Modifier = 0;
        return;
    }
    if ((s == 0x12) || (s == 0x59)) {
        Shift = 1;
    }
    if (Modifier) {
        return;
    }
    currentChar = s;
    printf("New rawChar: %d\n",currentChar);
    char c = Keymap[s + KeymapSize*Shift];
    if (c == 32 && s != 0x29) {
        return;
    }
    currentChar = c;
    printf("New Char: %c\n",currentChar);
}

void kmain() {
  printf("Hello, world! 😃\r\n");
  bool clockNew = true;
  bool dataBit = true;
  printf("Hello, world2! 😃\r\n");

  // When this function returns, the machine will reboot.
  //
  // In a real program, you probably wouldn't return from 
  // this function!
    turnOnRedLed();
    printf("Input adress: %p Data: %d Clock: %d\n", DUART_INPUTPORT, digitalRead(KBD_DATA_PIN),  digitalRead(KBD_CLOCK_PIN));
    turnOffRedLed();

  while (true) {
    clockNew = digitalRead(KBD_CLOCK_PIN);
    dataBit = digitalRead(KBD_DATA_PIN);
    // printf("Old: %d new: %d\n", clockOld, clockNew);
    //Detect falling edge
    if (clockOld && !clockNew) {

/*
        turnOnRedLed();
        printf("Data: %d \n", dataBit);
        turnOffRedLed();
*/

        handleNewDataBit(dataBit);
    }
    clockOld = clockNew;
  }
}