vbatts/grub
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

Rewrite spkmodem to use PIT for timing. Double the speed.

Browse source
This commit is contained in:
Vladimir 'phcoder' Serbinenko 2013-01-17 20:06:52 +01:00
parent 7d462559da
commit 17334a6b6a
4 changed files with 61 additions and 26 deletions
Download patch file Download diff file Expand all files Collapse all files

55
grub-core/term/spkmodem.c
View file

@ -30,30 +30,66 @@ GRUB_MOD_LICENSE ("GPLv3+");
extern struct grub_terminfo_output_state grub_spkmodem_terminfo_output;
static void
make_tone (grub_uint16_t freq_count, unsigned int duration)
{
/* Program timer 2. */
grub_outb (GRUB_PIT_CTRL_SELECT_2
| GRUB_PIT_CTRL_READLOAD_WORD
| GRUB_PIT_CTRL_SQUAREWAVE_GEN
| GRUB_PIT_CTRL_COUNT_BINARY, GRUB_PIT_CTRL);
grub_outb (freq_count & 0xff, GRUB_PIT_COUNTER_2); /* LSB */
grub_outb ((freq_count >> 8) & 0xff, GRUB_PIT_COUNTER_2); /* MSB */
/* Start speaker. */
grub_outb (grub_inb (GRUB_PIT_SPEAKER_PORT)
| GRUB_PIT_SPK_TMR2 | GRUB_PIT_SPK_DATA,
GRUB_PIT_SPEAKER_PORT);
for (; duration; duration--)
{
unsigned short counter, previous_counter = 0xffff;
while (1)
{
counter = grub_inb (GRUB_PIT_COUNTER_2);
counter |= ((grub_uint16_t) grub_inb (GRUB_PIT_COUNTER_2)) << 8;
if (counter > previous_counter)
{
previous_counter = counter;
break;
}
previous_counter = counter;
}
}
}
static int inited;
static void
put (struct grub_term_output *term __attribute__ ((unused)), const int c)
{
int i;
if (!inited)
{
make_tone (GRUB_SPEAKER_PIT_FREQUENCY / 50, 20);
inited = 1;
}
for (i = 7; i >= 0; i--)
{
if ((c >> i) & 1)
grub_speaker_beep_on (2000);
make_tone (GRUB_SPEAKER_PIT_FREQUENCY / 2000, 20);
else
grub_speaker_beep_on (4000);
grub_millisleep (10);
grub_speaker_beep_on (1000);
grub_millisleep (10);
make_tone (GRUB_SPEAKER_PIT_FREQUENCY / 4000, 40);
make_tone (GRUB_SPEAKER_PIT_FREQUENCY / 1000, 10);
}
grub_speaker_beep_on (50);
make_tone (GRUB_SPEAKER_PIT_FREQUENCY / 50, 0);
}
static grub_err_t
grub_spkmodem_init_output (struct grub_term_output *term)
{
grub_speaker_beep_on (50);
grub_millisleep (50);
grub_terminfo_output_init (term);
return 0;
@ -63,6 +99,7 @@ static grub_err_t
grub_spkmodem_fini_output (struct grub_term_output *term __attribute__ ((unused)))
{
grub_speaker_beep_off ();
inited = 0;
return 0;
}