subsystems/mvdm/ntvdm/hardware/ppi.c

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            subsystems/mvdm/ntvdm/hardware/ppi.c
   5  * PURPOSE:         Programmable Peripheral Interface emulation -
   6  *                  i8255A-5 compatible
   7  * PROGRAMMERS:     Hermes Belusca-Maito (hermes.belusca@sfr.fr)
   8  *
   9  * NOTES: - Most of its functionality as keyboard controller is replaced
  10  *          by the PS/2 controller.
  11  *        - This controller is here only for having ports 61h and 62h working.
  12  */
  13
  14 /* INCLUDES *******************************************************************/
  15
  16 #include "ntvdm.h"
  17
  18 #define NDEBUG
  19 #include <debug.h>
  20
  21 #include "emulator.h"
  22 #include "ppi.h"
  23
  24 #include "hardware/pit.h"
  25 #include "hardware/sound/speaker.h"
  26
  27 #include "io.h"
  28
  29 /* PRIVATE VARIABLES **********************************************************/
  30
  31 /*static*/ BYTE Port61hState = 0x00; // Used in emulator.c
  32 static     BYTE Port62hState = 0x00;
  33
  34 /* PRIVATE FUNCTIONS **********************************************************/
  35
  36 static BYTE WINAPI PpiReadPort(USHORT Port)
  37 {
  38     if (Port == PPI_PORT_61H)
  39         return Port61hState;
  40     else if (Port == PPI_PORT_62H)
  41         return Port62hState;
  42
  43     return 0x00;
  44 }
  45
  46 static VOID WINAPI Port61hWrite(USHORT Port, BYTE Data)
  47 {
  48     // BOOLEAN SpeakerStateChange = FALSE;
  49     BYTE OldPort61hState = Port61hState;
  50
  51     /* Only the four lowest bytes can be written */
  52     Port61hState = (Port61hState & 0xF0) | (Data & 0x0F);
  53
  54     if ((OldPort61hState ^ Port61hState) & 0x01)
  55     {
  56         DPRINT("PIT 2 Gate %s\n", Port61hState & 0x01 ? "on" : "off");
  57         PitSetGate(2, !!(Port61hState & 0x01));
  58         // SpeakerStateChange = TRUE;
  59     }
  60
  61     if ((OldPort61hState ^ Port61hState) & 0x02)
  62     {
  63         /* There were some change for the speaker... */
  64         DPRINT("Speaker %s\n", Port61hState & 0x02 ? "on" : "off");
  65         // SpeakerStateChange = TRUE;
  66     }
  67     // if (SpeakerStateChange) SpeakerChange(Port61hState);
  68     SpeakerChange(Port61hState);
  69 }
  70
  71 static VOID WINAPI Port62hWrite(USHORT Port, BYTE Data)
  72 {
  73     Port62hState = Data;
  74 }
  75
  76 /* PUBLIC FUNCTIONS ***********************************************************/
  77
  78 VOID PpiInitialize(VOID)
  79 {
  80     /* Register the I/O Ports */
  81     // Port 0x60 is now used by the PS/2 controller
  82     RegisterIoPort(PPI_PORT_61H, PpiReadPort, Port61hWrite);
  83     RegisterIoPort(PPI_PORT_62H, PpiReadPort, Port62hWrite);
  84     // Port 0x63 is unused
  85 }
  86
  87 /* EOF */