reactos/hal/halx86/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 <ddk/ntddk.h>
  14
  15 #define NDEBUG
  16 #include <internal/debug.h>
  17
  18
  19 /* CONSTANTS *****************************************************************/
  20
  21 #define TIMER2     0x42
  22 #define TIMER3     0x43
  23 #define PORT_B     0x61
  24 #define CLOCKFREQ  1193167
  25
  26
  27 /* FUNCTIONS *****************************************************************/
  28 /*
  29  * FUNCTION: Beeps the speaker.
  30  * ARGUMENTS:
  31  *       Frequency = If 0, the speaker will be switched off, otherwise
  32  *                   the speaker beeps with the specified frequency.
  33  */
  34
  35 BOOLEAN
  36 STDCALL
  37 HalMakeBeep (
  38         ULONG   Frequency
  39         )
  40 {
  41    UCHAR b;
  42
  43     /* save flags and disable interrupts */
  44     __asm__("pushf\n\t" \
  45             "cli\n\t");
  46
  47     /* speaker off */
  48     b = READ_PORT_UCHAR((PUCHAR)PORT_B);
  49     WRITE_PORT_UCHAR((PUCHAR)PORT_B, b & 0xFC);
  50
  51     if (Frequency)
  52     {
  53         DWORD Divider = CLOCKFREQ / Frequency;
  54
  55         if (Divider > 0x10000)
  56         {
  57             /* restore flags */
  58             __asm__("popf\n\t");
  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, READ_PORT_UCHAR((PUCHAR)PORT_B) | 0x03);
  70     }
  71
  72     /* restore flags */
  73     __asm__("popf\n\t");
  74
  75     return TRUE;
  76 }
  77