NT4/private/ntos/nthals/haldti/mips/jxbeep.c

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2001-01-01 00:00:00 +01:00
/*++
Copyright (c) 1991 Microsoft Corporation
Module Name:
jxbeep.c
Abstract:
This module implements the HAL speaker "beep" routines for a MIPS
system.
Author:
Environment:
Kernel mode
Revision History:
--*/
#include "halp.h"
#include "eisa.h"
BOOLEAN
HalMakeBeep(
IN ULONG Frequency
)
/*++
Routine Description:
This function sets the frequency of the speaker, causing it to sound a
tone. The tone will sound until the speaker is explicitly turned off,
so the driver is responsible for controlling the duration of the tone.
Arguments:
Frequency - Supplies the frequency of the desired tone. A frequency of
0 means the speaker should be shut off.
Return Value:
TRUE - Operation was successful (frequency within range or zero).
FALSE - Operation was unsuccessful (frequency was out of range).
Current tone (if any) is unchanged.
--*/
{
KIRQL oldIrql;
NMI_STATUS NmiStatus;
PEISA_CONTROL controlBase;
TIMER_CONTROL timerControl;
ULONG newCount;
controlBase = HalpEisaControlBase;
KeRaiseIrql(DISPATCH_LEVEL, &oldIrql);
//
// Stop the speaker.
//
*((PUCHAR) &NmiStatus) = READ_REGISTER_UCHAR(&controlBase->NmiStatus);
NmiStatus.SpeakerGate = 0;
NmiStatus.SpeakerData = 0;
WRITE_REGISTER_UCHAR(&controlBase->NmiStatus, *((PUCHAR) &NmiStatus));
if (Frequency == 0) {
KeLowerIrql(oldIrql);
return(TRUE);
}
//
// Calculate the new counter value.
//
newCount = (AT_BUS_OSC/12) / Frequency;
//
// The new count must be less than 16 bits in value.
//
if (newCount >= 0x10000) {
KeLowerIrql(oldIrql);
return(FALSE);
}
//
// Set the speaker timer to the correct mode.
//
timerControl.BcdMode = 0;
timerControl.Mode = TM_SQUARE_WAVE;
timerControl.SelectByte = SB_LSB_THEN_MSB;
timerControl.SelectCounter = SELECT_COUNTER_2;
WRITE_REGISTER_UCHAR(&controlBase->CommandMode1, *((PUCHAR) &timerControl));
//
// Set the speaker timer to the correct mode.
//
WRITE_REGISTER_UCHAR(&controlBase->SpeakerTone, (UCHAR)(newCount & 0xff));
WRITE_REGISTER_UCHAR(&controlBase->SpeakerTone, (UCHAR)(newCount >> 8));
//
// Start the speaker.
//
NmiStatus.SpeakerGate = 1;
NmiStatus.SpeakerData = 1;
WRITE_REGISTER_UCHAR(&controlBase->NmiStatus, *((PUCHAR) &NmiStatus));
KeLowerIrql(oldIrql);
return(TRUE);
}