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97 lines
2.1 KiB
C
97 lines
2.1 KiB
C
/*
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*
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* COPYRIGHT: See COPYING in the top level directory
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* PROJECT: ReactOS kernel
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* FILE: services/dd/mpu401/portio.c (see also mpu401.h)
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* PURPOSE: MPU-401 MIDI port I/O helper
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* PROGRAMMER: Andrew Greenwood
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* UPDATE HISTORY:
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* Sept 26, 2003: Created
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*/
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#include <ntddk.h>
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#include "mpu401.h"
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BOOLEAN WaitToSend(ULONG BasePort)
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{
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int TimeOut;
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DbgPrint("WaitToSend ");
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// Check if it's OK to send
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for (TimeOut = MPU401_TIMEOUT;
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! MPU401_READY_TO_SEND(BasePort) && TimeOut > 0;
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TimeOut --);
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// If a time-out occurs, we report failure
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if (! TimeOut)
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{
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DbgPrint("FAILED\n");
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return FALSE;
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}
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DbgPrint("SUCCEEDED\n");
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return TRUE;
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}
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BOOLEAN WaitToReceive(ULONG BasePort)
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{
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int TimeOut;
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DbgPrint("WaitToSend ");
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// Check if it's OK to receive
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for (TimeOut = MPU401_TIMEOUT;
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! MPU401_READY_TO_RECEIVE(BasePort) && TimeOut > 0;
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TimeOut --);
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// If a time-out occurs, we report failure
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if (! TimeOut)
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{
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DbgPrint("FAILED\n");
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return FALSE;
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}
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DbgPrint("SUCCEEDED\n");
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return TRUE;
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}
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BOOLEAN InitUARTMode(ULONG BasePort)
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{
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ULONG TimeOut;
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UCHAR Status = 0;
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DbgPrint("InitUARTMode() called\n");
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// Check if it's OK to send
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if (! WaitToSend(BasePort))
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return FALSE;
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DbgPrint("Resetting MPU401\n");
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// Send an MPU reset:
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MPU401_WRITE_COMMAND(BasePort, 0xff);
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// Check if it's OK to receive (some cards will ignore the above reset
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// command and so will not issue an ACK, so time out is NOT an error)
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DbgPrint("Waiting for an ACK\n");
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if (WaitToReceive(BasePort))
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{
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// Check to make sure the reset was acknowledged:
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for (TimeOut = MPU401_TIMEOUT;
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(Status = (MPU401_READ_DATA(BasePort) & 0xfe) && TimeOut > 0);
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TimeOut --);
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}
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DbgPrint("Entering UART mode\n");
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// Now we kick the MPU401 into UART ("dumb") mode
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MPU401_WRITE_COMMAND(BasePort, 0x3f);
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return TRUE;
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}
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