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:            subsystems/mvdm/ntvdm/hardware/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 /* DEFINES ********************************************************************/
  15
  16 #define PIT_CHANNELS 3
  17 #define PIT_BASE_FREQUENCY 1193182LL
  18 #define PIT_DATA_PORT(x) (0x40 + (x))
  19 #define PIT_COMMAND_PORT 0x43
  20
  21 #define WRITE_PIT_VALUE(PitChannel, Value)    \
  22     (PitChannel).Bcd ? BCD_TO_BINARY(Value) : (Value)
  23
  24 #define READ_PIT_VALUE(PitChannel, Value)     \
  25     (PitChannel).Bcd ? BINARY_TO_BCD(Value) : (Value)
  26
  27 typedef enum _PIT_MODE
  28 {
  29     PIT_MODE_INT_ON_TERMINAL_COUNT,
  30     PIT_MODE_HARDWARE_ONE_SHOT,
  31     PIT_MODE_RATE_GENERATOR,
  32     PIT_MODE_SQUARE_WAVE,
  33     PIT_MODE_SOFTWARE_STROBE,
  34     PIT_MODE_HARDWARE_STROBE
  35 } PIT_MODE, *PPIT_MODE;
  36
  37 typedef VOID (WINAPI *PIT_OUT_FUNCTION)(LPVOID Param, BOOLEAN State);
  38
  39 typedef struct _PIT_CHANNEL
  40 {
  41     /* PIT Status fields */
  42     PIT_MODE Mode;
  43     BOOLEAN  Bcd;
  44     BYTE     ReadWriteMode; // 0 --> Counter Latch ; 1 --> LSB R/W ; 2 --> MSB R/W ; 3 --> LSB then MSB R/W
  45
  46     /* For interleaved reading and writing in 2-byte RW mode */
  47     BYTE    ReadStatus;     // Same convention as ReadWriteMode
  48     BYTE    WriteStatus;    // Same convention as ReadWriteMode
  49
  50     /* For reading the PIT status byte */
  51     BOOLEAN LatchStatusSet;
  52     BYTE    StatusLatch;
  53
  54     /* Counting */
  55     BOOLEAN Gate;
  56
  57     /**/WORD    CountRegister;/**/  // Our ReloadValue ???
  58     WORD OutputLatch;
  59     /*******************************/
  60
  61     WORD    ReloadValue;    // Max value of the counter
  62     WORD    CurrentValue;   // Real value of the counter
  63
  64     /* PIT Output */
  65     BOOLEAN Out;    // 0: Low ; 1: High
  66     /** HACK!! **/BOOLEAN FlipFlop;/** HACK!! **/
  67     LPVOID           OutParam;
  68     PIT_OUT_FUNCTION OutFunction;
  69
  70 } PIT_CHANNEL, *PPIT_CHANNEL;
  71
  72 /* FUNCTIONS ******************************************************************/
  73
  74 VOID PitSetOutFunction(BYTE Channel, LPVOID Param, PIT_OUT_FUNCTION OutFunction);
  75 VOID PitSetGate(BYTE Channel, BOOLEAN State);
  76 WORD PitGetReloadValue(BYTE Channel);
  77
  78 VOID PitInitialize(VOID);
  79
  80 #endif // _PIT_H_
  81
  82 /* EOF */