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