arch/all-pc/boot/grub2-aros/include/grub/speaker.h

   1 #ifndef GRUB_SPEAKER_HEADER
   2 #define GRUB_SPEAKER_HEADER 1
   3
   4 #include <grub/cpu/io.h>
   5 #include <grub/i386/pit.h>
   6
   7 /* The frequency of the PIT clock.  */
   8 #define GRUB_SPEAKER_PIT_FREQUENCY              0x1234dd
   9
  10 static inline void
  11 grub_speaker_beep_off (void)
  12 {
  13   unsigned char status;
  14
  15   status = grub_inb (GRUB_PIT_SPEAKER_PORT);
  16   grub_outb (status & ~(GRUB_PIT_SPK_TMR2 | GRUB_PIT_SPK_DATA),
  17              GRUB_PIT_SPEAKER_PORT);
  18 }
  19
  20 static inline void
  21 grub_speaker_beep_on (grub_uint16_t pitch)
  22 {
  23   unsigned char status;
  24   unsigned int counter;
  25
  26   if (pitch < 20)
  27     pitch = 20;
  28   else if (pitch > 20000)
  29     pitch = 20000;
  30
  31   counter = GRUB_SPEAKER_PIT_FREQUENCY / pitch;
  32
  33   /* Program timer 2.  */
  34   grub_outb (GRUB_PIT_CTRL_SELECT_2
  35              | GRUB_PIT_CTRL_READLOAD_WORD
  36              | GRUB_PIT_CTRL_SQUAREWAVE_GEN
  37              | GRUB_PIT_CTRL_COUNT_BINARY, GRUB_PIT_CTRL);
  38   grub_outb (counter & 0xff, GRUB_PIT_COUNTER_2);               /* LSB */
  39   grub_outb ((counter >> 8) & 0xff, GRUB_PIT_COUNTER_2);        /* MSB */
  40
  41   /* Start speaker.  */
  42   status = grub_inb (GRUB_PIT_SPEAKER_PORT);
  43   grub_outb (status | GRUB_PIT_SPK_TMR2 | GRUB_PIT_SPK_DATA,
  44              GRUB_PIT_SPEAKER_PORT);
  45 }
  46
  47 #endif