reactos/hal/halx86/generic/beep.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            ntoskrnl/hal/x86/beep.c
   5  * PURPOSE:         Speaker function (it's only one)
   6  * PROGRAMMER:      Eric Kohl (ekohl@abo.rhein-zeitung.de)
   7  * UPDATE HISTORY:
   8  *                  Created 31/01/99
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <hal.h>
  14 #define NDEBUG
  15 #include <debug.h>
  16
  17
  18 /* CONSTANTS *****************************************************************/
  19
  20 #define TIMER2     0x42
  21 #define TIMER3     0x43
  22 #define PORT_B     0x61
  23 #define CLOCKFREQ  1193167
  24
  25
  26 /* FUNCTIONS *****************************************************************/
  27 /*
  28  * FUNCTION: Beeps the speaker.
  29  * ARGUMENTS:
  30  *       Frequency = If 0, the speaker will be switched off, otherwise
  31  *                   the speaker beeps with the specified frequency.
  32  */
  33
  34 BOOLEAN
  35 STDCALL
  36 HalMakeBeep (
  37         ULONG   Frequency
  38         )
  39 {
  40     UCHAR b;
  41     ULONG flags;
  42
  43     /* save flags and disable interrupts */
  44     Ki386SaveFlags(flags);
  45     Ki386DisableInterrupts();
  46
  47     /* speaker off */
  48     b = READ_PORT_UCHAR((PUCHAR)PORT_B);
  49     WRITE_PORT_UCHAR((PUCHAR)PORT_B, (UCHAR)(b & 0xFC));
  50
  51     if (Frequency)
  52     {
  53         DWORD Divider = CLOCKFREQ / Frequency;
  54
  55         if (Divider > 0x10000)
  56         {
  57             /* restore flags */
  58             Ki386RestoreFlags(flags);
  59
  60             return FALSE;
  61         }
  62
  63         /* set timer divider */
  64         WRITE_PORT_UCHAR((PUCHAR)TIMER3, 0xB6);
  65         WRITE_PORT_UCHAR((PUCHAR)TIMER2, (UCHAR)(Divider & 0xFF));
  66         WRITE_PORT_UCHAR((PUCHAR)TIMER2, (UCHAR)((Divider>>8) & 0xFF));
  67
  68         /* speaker on */
  69         WRITE_PORT_UCHAR((PUCHAR)PORT_B, (UCHAR)(READ_PORT_UCHAR((PUCHAR)PORT_B) | 0x03));
  70     }
  71
  72     /* restore flags */
  73     Ki386RestoreFlags(flags);
  74
  75     return TRUE;
  76 }
  77