reactos/subsystems/mvdm/ntvdm/hardware/pit.h

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            pit.h
   5  * PURPOSE:         Programmable Interval Timer emulation -
   6  *                  i82C54/8254 compatible
   7  * PROGRAMMERS:     Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
   8  *                  Hermes Belusca-Maito (hermes.belusca@sfr.fr)
   9  */
  10
  11 #ifndef _PIT_H_
  12 #define _PIT_H_
  13
  14 /* INCLUDES *******************************************************************/
  15
  16 #include "ntvdm.h"
  17
  18 /* DEFINES ********************************************************************/
  19
  20 #define PIT_CHANNELS 3
  21 #define PIT_BASE_FREQUENCY 1193182LL
  22 #define PIT_DATA_PORT(x) (0x40 + (x))
  23 #define PIT_COMMAND_PORT 0x43
  24
  25 #define WRITE_PIT_VALUE(PitChannel, Value)    \
  26     (PitChannel).Bcd ? BCD_TO_BINARY(Value) : (Value)
  27
  28 #define READ_PIT_VALUE(PitChannel, Value)     \
  29     (PitChannel).Bcd ? BINARY_TO_BCD(Value) : (Value)
  30
  31 typedef enum _PIT_MODE
  32 {
  33     PIT_MODE_INT_ON_TERMINAL_COUNT,
  34     PIT_MODE_HARDWARE_ONE_SHOT,
  35     PIT_MODE_RATE_GENERATOR,
  36     PIT_MODE_SQUARE_WAVE,
  37     PIT_MODE_SOFTWARE_STROBE,
  38     PIT_MODE_HARDWARE_STROBE
  39 } PIT_MODE, *PPIT_MODE;
  40
  41 typedef VOID (WINAPI *PIT_OUT_FUNCTION)(LPVOID Param, BOOLEAN State);
  42
  43 typedef struct _PIT_CHANNEL
  44 {
  45     /* PIT Status fields */
  46     PIT_MODE Mode;
  47     BOOLEAN  Bcd;
  48     BYTE     ReadWriteMode; // 0 --> Counter Latch ; 1 --> LSB R/W ; 2 --> MSB R/W ; 3 --> LSB then MSB R/W
  49
  50     /* For interleaved reading and writing in 2-byte RW mode */
  51     BYTE    ReadStatus;     // Same convention as ReadWriteMode
  52     BYTE    WriteStatus;    // Same convention as ReadWriteMode
  53
  54     /* For reading the PIT status byte */
  55     BOOLEAN LatchStatusSet;
  56     BYTE    StatusLatch;
  57
  58     /* Counting */
  59     BOOLEAN Gate;
  60
  61     /**/WORD    CountRegister;/**/  // Our ReloadValue ???
  62     WORD OutputLatch;
  63     /*******************************/
  64
  65     WORD    ReloadValue;    // Max value of the counter
  66     WORD    CurrentValue;   // Real value of the counter
  67
  68     /* PIT Output */
  69     BOOLEAN Out;    // 0: Low ; 1: High
  70     /** HACK!! **/BOOLEAN FlipFlop;/** HACK!! **/
  71     LPVOID           OutParam;
  72     PIT_OUT_FUNCTION OutFunction;
  73
  74 } PIT_CHANNEL, *PPIT_CHANNEL;
  75
  76 /* FUNCTIONS ******************************************************************/
  77
  78 VOID PitSetOutFunction(BYTE Channel, LPVOID Param, PIT_OUT_FUNCTION OutFunction);
  79 VOID PitSetGate(BYTE Channel, BOOLEAN State);
  80 WORD PitGetReloadValue(BYTE Channel);
  81
  82 VOID PitInitialize(VOID);
  83
  84 #endif // _PIT_H_
  85
  86 /* EOF */