blob: d39405c7820905674931b369a10ef731845c040a (
plain) (
tree)
|
|
#ident "@(#) NEC jxbeep.c 1.2 94/10/17 11:22:04"
/*++
Copyright (c) 1991-1994 Microsoft Corporation
Module Name:
jxbeep.c
Abstract:
This module implements the HAL speaker "beep" routines for a MIPS
system.
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 = HalpEisaControlBase;
TIMER_CONTROL timerControl;
ULONG newCount;
BOOLEAN Result;
//
// Raise IRQL to dispatch level and acquire the beep spin lock.
//
KeAcquireSpinLock(&HalpBeepLock, &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 the specified frequency is zero, then the speaker is to be stopped.
//
if (Frequency == 0) {
Result = TRUE;
} else {
//
// If the new count has a magnitude less than 65,536 (0x10000), then
// set the speaker time to the correct mode. Otherwise, return a value
// of FALSE sinc ethe frequency is out of range.
//
newCount = TIMER_CLOCK_IN / Frequency;
if (newCount >= 0x10000) {
Result = FALSE;
} else {
//
// 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));
Result = TRUE;
}
}
//
// Release the beep spin lock and lower IRQL to its previous value.
//
KeReleaseSpinLock(&HalpBeepLock, OldIrql);
return Result;
}
|
