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

//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:       Speaker 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/speaker.h>
#include <kernel/iomisc.h>
#include <kernel/time.h>

void IoStartSpeaker(int freq)
{
    char temp;
    int pitf = 1193180 / freq;
    
    ulong flags = KePauseIRQs();
    IoWriteByteOnPort(0x43, 0xB6);
    IoWriteByteOnPort(0x42, (char)pitf);
    IoWriteByteOnPort(0x42, (char)(pitf >> 8));
    
    temp = IoReadByteFromPort(0x61);
    if (temp != (temp | 3)) {
        IoWriteByteOnPort(0x61, temp | 3);
    }
    KeRestoreIRQs(flags);
}

void IoQuietSpeaker(void)
{
    IoWriteByteOnPort(0x61, IoReadByteFromPort(0x61) & 0xFC);
}

void IoDoBeep(void)
{

    IoStartSpeaker(1000);

    // Worst possible way of waiting
    // We need actual timers
    ulong ticks = IoGetRtcTicks();
    while (IoGetRtcTicks() < ticks + 512);

    IoQuietSpeaker();

}