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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2007 Advanced Micro Devices, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdint.h>
#include <delay.h>
#include <cpu/x86/msr.h>
#include <cpu/x86/lapic.h>
/* NOTE: We use the APIC TIMER register is to hold flags for AP init during
* pre-memory init (ROMCC). Don't use init_timer() and udelay is redirected
* to udelay_tsc().
*/
void init_timer(void)
{
/* Set the apic timer to no interrupts and periodic mode */
lapic_write(LAPIC_LVTT, (1 << 17)|(1<< 16)|(0 << 12)|(0 << 0));
/* Set the divider to 1, no divider */
lapic_write(LAPIC_TDCR, LAPIC_TDR_DIV_1);
/* Set the initial counter to 0xffffffff */
lapic_write(LAPIC_TMICT, 0xffffffff);
}
void udelay(u32 usecs)
{
u32 start, value, ticks;
/* Calculate the number of ticks to run, our FSB runs a 200Mhz */
ticks = usecs * 200;
start = lapic_read(LAPIC_TMCCT);
do {
value = lapic_read(LAPIC_TMCCT);
} while((start - value) < ticks);
}
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