reactos/drivers/dd/blue/portio.c

   1 /*
   2  *
   3  * COPYRIGHT:            See COPYING in the top level directory
   4  * PROJECT:              ReactOS kernel
   5  * FILE:                 services/dd/mpu401/portio.c (see also mpu401.h)
   6  * PURPOSE:              MPU-401 MIDI port I/O helper
   7  * PROGRAMMER:           Andrew Greenwood
   8  * UPDATE HISTORY:
   9  *                       Sept 26, 2003: Created
  10  */
  11
  12 #include <windows.h>
  13 #include <ddk/ntddk.h>
  14 #include "mpu401.h"
  15
  16
  17 BOOLEAN WaitToSend(UINT BasePort)
  18 {
  19     int TimeOut;
  20
  21     DbgPrint("WaitToSend ");
  22
  23     // Check if it's OK to send
  24     for (TimeOut = MPU401_TIMEOUT;
  25          ! MPU401_READY_TO_SEND(BasePort) && TimeOut > 0;
  26          TimeOut --);
  27
  28     // If a time-out occurs, we report failure
  29     if (! TimeOut)
  30     {
  31         DbgPrint("FAILED\n");
  32         return FALSE;
  33     }
  34
  35     DbgPrint("SUCCEEDED\n");
  36
  37     return TRUE;
  38 }
  39
  40
  41 BOOLEAN WaitToReceive(UINT BasePort)
  42 {
  43     int TimeOut;
  44
  45     DbgPrint("WaitToSend ");
  46
  47     // Check if it's OK to receive
  48     for (TimeOut = MPU401_TIMEOUT;
  49          ! MPU401_READY_TO_RECEIVE(BasePort) && TimeOut > 0;
  50          TimeOut --);
  51
  52     // If a time-out occurs, we report failure
  53     if (! TimeOut)
  54     {
  55         DbgPrint("FAILED\n");
  56         return FALSE;
  57     }
  58
  59     DbgPrint("SUCCEEDED\n");
  60
  61     return TRUE;
  62 }
  63
  64
  65 BOOLEAN InitUARTMode(UINT BasePort)
  66 {
  67     UINT TimeOut;
  68     UCHAR Status = 0;
  69
  70     DbgPrint("InitUARTMode() called\n");
  71
  72     // Check if it's OK to send
  73     if (! WaitToSend(BasePort))
  74         return FALSE;
  75
  76     DbgPrint("Resetting MPU401\n");
  77
  78     // Send an MPU reset:
  79     MPU401_WRITE_COMMAND(BasePort, 0xff);
  80
  81     // Check if it's OK to receive (some cards will ignore the above reset
  82     // command and so will not issue an ACK, so time out is NOT an error)
  83     DbgPrint("Waiting for an ACK\n");
  84     if (WaitToReceive(BasePort))
  85     {
  86         // Check to make sure the reset was acknowledged:
  87         for (TimeOut = MPU401_TIMEOUT;
  88              Status = (MPU401_READ_DATA(BasePort) & 0xfe) && TimeOut > 0;
  89              TimeOut --);
  90     }
  91
  92     DbgPrint("Entering UART mode\n");
  93     // Now we kick the MPU401 into UART ("dumb") mode
  94     MPU401_WRITE_COMMAND(BasePort, 0x3f);
  95
  96     return TRUE;
  97 }