//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:  Interrupt 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 <kernel/base.h>
#include <kernel/iomisc.h>
#include <extras/buf.h>

extern void RtcIsr(void);
extern void SendEOItoPIC(void);
extern void IdtRegisterIrq(void (*isr)(void), uchar irq, uchar flags);

ulong IoRtcTicks = 0;

void IoSetupRtc(void)
{
    IdtRegisterIrq(RtcIsr, 0x28, 0x8E);
}

void IoEnableRtc(void)
{
    ulong flags = KePauseIRQs();
    char readedInterruptConfig;
    char readedRegister;
    char readedIrqs;
    uchar RtcRate;

    // Setting up the register control and interrupt rates
    RtcRate = 0x05;

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

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

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

    // clean-up
    IoWriteByteOnPort(0x70, 0x0C);                  // Select status reg C
    IoReadByteFromPort(0x71);                       // Flush
    KeRestoreIRQs(flags);
}

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