mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-14 08:57:58 +00:00
da3fe24759
Rename pcat_timer.c to i8254.c and pcat_interrupts.c to i8259.c, to match their header file names (i8254.h and i8259.h). Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Acked-by: Simon Glass <sjg@chromium.org>
37 lines
967 B
C
37 lines
967 B
C
/*
|
|
* (C) Copyright 2002
|
|
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <asm/io.h>
|
|
#include <asm/i8254.h>
|
|
|
|
#define TIMER1_VALUE 18 /* 15.6us */
|
|
#define TIMER2_VALUE 0x0a8e /* 440Hz */
|
|
|
|
int i8254_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.
|
|
* To stop it, clear both bit0 and bit1 of port 0x61.
|
|
*/
|
|
outb(PIT_CMD_CTR2 | PIT_CMD_BOTH | PIT_CMD_MODE3,
|
|
PIT_BASE + PIT_COMMAND);
|
|
outb(TIMER2_VALUE & 0xff, PIT_BASE + PIT_T2);
|
|
outb(TIMER2_VALUE >> 8, PIT_BASE + PIT_T2);
|
|
|
|
return 0;
|
|
}
|