os-k/kaleid/kernel/io/rtc.c

//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:  RTC Time  related functions                                        //
//                                                                            //
//                                                                            //
//  Copyright © 2018-2019 The OS/K Team                                       //
//                                                                            //
//  This file is part of OS/K.                                                //
//                                                                            //
//  OS/K 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         //
//  any later version.                                                        //
//                                                                            //
//  OS/K 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 OS/K.  If not, see <https://www.gnu.org/licenses/>.            //
//----------------------------------------------------------------------------//

#include <lib/buf.h>
#include <ke/time.h>

static ulong IoRtcTicks = 0;
static char IoTimeChar[22] = { 0 };
static uchar RtcRate = 0x05; //2048Hz
static Time_t IoRtcOriginTime;
static Time_t IoRtcTime;
static char time24or12Mode;

static void GetTimeFromRtc(void)
{
    Time_t lastTime;

    char updateInProgress = 1;

    while(updateInProgress) {                       // wait while the RTC updates its value
        IoWriteByteOnPort(0x70, 0x0A);
        updateInProgress = (IoReadByteFromPort(0x71) & 0x80);
    }

    IoWriteByteOnPort(0x70, 0x0);
    IoRtcOriginTime.sec = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x02);
    IoRtcOriginTime.min = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x04);
    IoRtcOriginTime.hour = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x06);
    IoRtcOriginTime.weekday = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x07);
    IoRtcOriginTime.day = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x08);
    IoRtcOriginTime.month = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x09);
    IoRtcOriginTime.year = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x32);
    IoRtcOriginTime.century = IoReadByteFromPort(0x71);

    // Now while we don't get the same value, read the registers (ensure data are valid)
    do {
        lastTime.sec = IoRtcOriginTime.sec;
        lastTime.min = IoRtcOriginTime.min;
        lastTime.hour = IoRtcOriginTime.hour;
        lastTime.weekday = IoRtcOriginTime.weekday;
        lastTime.day = IoRtcOriginTime.day;
        lastTime.month = IoRtcOriginTime.month;
        lastTime.year = IoRtcOriginTime.year;
        lastTime.century = IoRtcOriginTime.century;

        while(updateInProgress) {                       // wait while the RTC updates its value
            IoWriteByteOnPort(0x70, 0x0A);
            updateInProgress = (IoReadByteFromPort(0x71) & 0x80);
        }

        IoWriteByteOnPort(0x70, 0x0);
        IoRtcOriginTime.sec = IoReadByteFromPort(0x71);
        IoWriteByteOnPort(0x70, 0x02);
        IoRtcOriginTime.min = IoReadByteFromPort(0x71);
        IoWriteByteOnPort(0x70, 0x04);
        IoRtcOriginTime.hour = IoReadByteFromPort(0x71);
        IoWriteByteOnPort(0x70, 0x06);
        IoRtcOriginTime.weekday = IoReadByteFromPort(0x71);
        IoWriteByteOnPort(0x70, 0x07);
        IoRtcOriginTime.day = IoReadByteFromPort(0x71);
        IoWriteByteOnPort(0x70, 0x08);
        IoRtcOriginTime.month = IoReadByteFromPort(0x71);
        IoWriteByteOnPort(0x70, 0x09);
        IoRtcOriginTime.year = IoReadByteFromPort(0x71);
        IoWriteByteOnPort(0x70, 0x32);
        IoRtcOriginTime.century = IoReadByteFromPort(0x71);

    } while ( (lastTime.sec  != IoRtcOriginTime.sec) || (lastTime.min  != IoRtcOriginTime.min) ||
              (lastTime.hour  != IoRtcOriginTime.hour) || (lastTime.weekday  != IoRtcOriginTime.weekday) ||
              (lastTime.day  != IoRtcOriginTime.day) || (lastTime.month  != IoRtcOriginTime.month) ||
              (lastTime.year  != IoRtcOriginTime.year) || (lastTime.century  != IoRtcOriginTime.century)
          );

    IoWriteByteOnPort(0x70, 0x0B);
    time24or12Mode = IoReadByteFromPort(0x71);
    // Convert to binary if it is necessary
    if (!(time24or12Mode & 0x04)) {
        IoRtcOriginTime.sec = (IoRtcOriginTime.sec & 0x0F)
                        + ((IoRtcOriginTime.sec / 16) * 10);
        IoRtcOriginTime.min = (IoRtcOriginTime.min & 0x0F)
                        + ((IoRtcOriginTime.min / 16) * 10);
        IoRtcOriginTime.hour = ( (IoRtcOriginTime.hour & 0x0F)
                        + (((IoRtcOriginTime.hour & 0x70) / 16) * 10) )
                        | (IoRtcOriginTime.hour & 0x80);
        IoRtcOriginTime.day = (IoRtcOriginTime.day & 0x0F) + ((IoRtcOriginTime.day / 16) * 10);
        IoRtcOriginTime.month = (IoRtcOriginTime.month & 0x0F)
                        + ((IoRtcOriginTime.month / 16) * 10);
        IoRtcOriginTime.year = (IoRtcOriginTime.year & 0x0F)
                        + ((IoRtcOriginTime.year / 16) * 10);
        IoRtcOriginTime.century = (IoRtcOriginTime.century & 0x0F)
                        + ((IoRtcOriginTime.century / 16) * 10);
        IoRtcOriginTime.weekday = (IoRtcOriginTime.weekday & 0x0F)
                        + ((IoRtcOriginTime.weekday / 16) * 10);
    }

    // Convert 12 to 24 hour if necessary
    if (!(time24or12Mode & 0x02) && (IoRtcOriginTime.hour & 0x80)) {
        IoRtcOriginTime.hour = ((IoRtcOriginTime.hour & 0x7)+ 10) % 24;
    }

    IoRtcTime.sec = IoRtcOriginTime.sec;
    IoRtcTime.min = IoRtcOriginTime.min;
    IoRtcTime.hour = IoRtcOriginTime.hour;
    IoRtcTime.weekday = IoRtcOriginTime.weekday;
    IoRtcTime.day = IoRtcOriginTime.day;
    IoRtcTime.month = IoRtcOriginTime.month;
    IoRtcTime.year = IoRtcOriginTime.year;
    IoRtcTime.century = IoRtcOriginTime.century;
}

void RtcHandler(ISRFrame_t *regs)
{
    //bprintf(BStdOut, " *RTC - ");
    IoWriteByteOnPort(0x70, 0x0C);  // Selects status reg C
    IoReadByteFromPort(0x71);       // Flush
    IoRtcTicks++;
    IoSendEOItoPIC(0x28);
    //bprintf(BStdOut, " - EOI* ");
}

void IoPrintRtcTime(void)
{
    Time_t* RtcTime = IoGetRtcTime();
    KernLog("[RTC Time] %02d/%02d/%04d ; %02d:%02d:%02d \n",
            RtcTime->day,
            RtcTime->month,
            RtcTime->year + RtcTime->century*100,
            RtcTime->hour,
            RtcTime->min,
            RtcTime->sec
            );
}

char* IoGetRtcTimeChar(void)
{
    Time_t *RtcTime = IoGetRtcTime();
    snprintf(IoTimeChar, sizeof(IoTimeChar),
            "%02d/%02d/%02d ; %02d:%02d:%02d",
            RtcTime->day,
            RtcTime->month,
            RtcTime->year + RtcTime->century*100,
            RtcTime->hour,
            RtcTime->min,
            RtcTime->sec
            );
    return IoTimeChar;
}


static void UpdateRtcTime(void)
{
    ulong frequency = 32768 >> (RtcRate-1);
    uchar minRemain, hourRemain, dayRemain;

    IoRtcTime.sec =
            (uchar)(((ulong)IoRtcOriginTime.sec + (IoRtcTicks / frequency)) % 60);
    minRemain =
            (uchar)(((ulong)IoRtcOriginTime.sec + (IoRtcTicks / frequency)) / 60);

    IoRtcTime.min =
            (uchar)(((ulong)IoRtcOriginTime.min +  minRemain) % 60);
    hourRemain =
            (uchar)(((ulong)IoRtcOriginTime.min +  minRemain) / 60);

    IoRtcTime.hour =
            (uchar)(((ulong)IoRtcOriginTime.hour +  hourRemain) % 24);
    dayRemain =
            (uchar)(((ulong)IoRtcOriginTime.hour +  hourRemain) / 24);

    if (dayRemain) {
       KeStartPanic("[RTC Time] We must shutdown this computer for your safety.\n");
    }
}

Time_t* IoGetRtcTime(void)
{
    UpdateRtcTime();
    return &IoRtcTime;
}

static uint IsLeapYear(uint year)
{
    if (!(year % 4)) {
        return 0;
    }
    
    return year % 100 == 0
            ? (year % 400 == 0)
            : 1;
}

static uint DaysInMonth(uint month, uint year)
{
    return (month == 2)
            ? (28 + IsLeapYear(year))
            : 31 - (month - 1) % 7 % 2;
}

ulong IoGetTimeStamp(void)
{
    Time_t *time = IoGetRtcTime();
    
    uint dpy = 365 + IsLeapYear(time->year);
    uint dim = DaysInMonth(time->month, time->year + time->century * 100);
    
    return time->sec
         + time->min  * 60
         + time->hour * 60 * 60
         + time->day  * 24 * 60 * 60
         + time->month * dim * 24 * 60 * 60
         + (time->year + time->century * 100)
             * dpy * 24 * 60 * 60;
}

ulong IoGetRtcTicks(void)
{
    return IoRtcTicks;
}

void IoEnableRtc(void)
{
    ulong flags = KePauseIRQs();
    char readInterruptConfig;
    char readRegister;
    char readIrqs;

    IdtRegisterIsr(RtcHandler, 0x28);

    // Setting up the register control and interrupt rates
    DebugLog("[RTC Time] Interrupt frequency set to %d Hz\n",
              32768 >> (RtcRate-1));

    IoWriteByteOnPort(0x70, 0x8B);
    readRegister = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x8B);                  // Because reading flushes
    IoWriteByteOnPort(0x71, readRegister | 0x40);

    IoWriteByteOnPort(0x70, 0x8A);
    readInterruptConfig = IoReadByteFromPort(0x71);
    IoWriteByteOnPort(0x70, 0x8A);                  // Because reading flushes
    IoWriteByteOnPort(0x71, (readInterruptConfig & 0xF0) | RtcRate);
    IoWriteByteOnPort(0x70, 0x0C);
    IoReadByteFromPort(0x71);                       // Flush

    // Setting up the IRQs
    readIrqs = IoReadByteFromPort(0xA1);
    IoWriteByteOnPort(0xA1, 0xFE & readIrqs);     // Enables IRQ on PIC 2
    readIrqs = IoReadByteFromPort(0x21);
    IoWriteByteOnPort(0x21, 0xFB & readIrqs);     // Enables IRQ on PIC 1

    // Clean-up
    IoWriteByteOnPort(0x70, 0x0C);                  // Select status reg C
    IoReadByteFromPort(0x71);                       // Flush

    GetTimeFromRtc();
    KeRestoreIRQs(flags);
    IoEnableNMI();
    
    srand(IoGetTimeStamp());
}

void IoRtcWait(uint time)   // time in ms
{
    ulong frequency = 32768 >> (RtcRate-1);
    ulong beginTick = IoGetRtcTicks();
    while(IoGetRtcTicks() < beginTick + (frequency/1000) * time) {
        KePauseCPU();
    }

}