mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-10-05 11:00:43 +09:00
x86: Initialize i8254 timer counter 1
Initialize counter 1, used to refresh request signal. This is required for legacy purpose as some codes like vgabios utilizes counter 1 to provide delay functionality. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Acked-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
parent
0a2ea02068
commit
bffeed0158
@ -9,10 +9,20 @@
|
||||
#include <asm/io.h>
|
||||
#include <asm/i8254.h>
|
||||
|
||||
#define TIMER1_VALUE 18 /* 15.6us */
|
||||
#define TIMER2_VALUE 0x0a8e /* 440Hz */
|
||||
|
||||
int pcat_timer_init(void)
|
||||
{
|
||||
/*
|
||||
* Initialize counter 1, used to refresh request signal.
|
||||
* This is required for legacy purpose as some codes like
|
||||
* vgabios utilizes counter 1 to provide delay functionality.
|
||||
*/
|
||||
outb(PIT_CMD_CTR1 | PIT_CMD_LOW | PIT_CMD_MODE2,
|
||||
PIT_BASE + PIT_COMMAND);
|
||||
outb(TIMER1_VALUE, PIT_BASE + PIT_T1);
|
||||
|
||||
/*
|
||||
* Initialize counter 2, used to drive the speaker.
|
||||
* To start a beep, set both bit0 and bit1 of port 0x61.
|
||||
|
Loading…
Reference in New Issue
Block a user