/*
* Copyright (C) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch/types.h>
#include <time/clock.h>
#include <time/delay.h>
#include <arch/interrupt.h>
#include <arch/i8259.h>
#include <arch/i8254.h>
#include <cpu.h>
#include <config.h>
#include <arch/pm.h>
#include <arch/asm.h>
#include <arch/cpuid.h>
#include <arch.h>
#include <time/delay.h>
/*
* i8254 chip driver.
* Low level time functions.
*/
#define CLK_PORT1 0x40
#define CLK_PORT4 0x43
#define CLK_CONST 1193180
#define MAGIC_NUMBER 1194
void i8254_init(void)
{
i8254_normal_operation();
}
void i8254_normal_operation(void)
{
outb(CLK_PORT4, 0x36);
pic_disable_irqs(1<<IRQ_CLK);
outb(CLK_PORT1, (CLK_CONST/HZ) & 0xf);
outb(CLK_PORT1, (CLK_CONST/HZ) >> 8);
pic_enable_irqs(1<<IRQ_CLK);
trap_register(VECTOR_CLK, i8254_interrupt);
}
#define LOOPS 150000
#define SHIFT 11
void i8254_calibrate_delay_loop(void)
{
__u64 clk1, clk2;
__u32 t1, t2, o1, o2;
__u8 not_ok;
/*
* One-shot timer. Count-down from 0xffff at 1193180Hz
* MAGIC_NUMBER is the magic value for 1ms.
*/
outb(CLK_PORT4, 0x30);
outb(CLK_PORT1, 0xff);
outb(CLK_PORT1, 0xff);
do {
/* will read both status and count */
outb(CLK_PORT4, 0xc2);
not_ok = (inb(CLK_PORT1)>>6)&1;
t1 = inb(CLK_PORT1);
t1 |= inb(CLK_PORT1) << 8;
} while (not_ok);
asm_delay_loop(LOOPS);
outb(CLK_PORT4, 0xd2);
t2 = inb(CLK_PORT1);
t2 |= inb(CLK_PORT1) << 8;
/*
* We want to determine the overhead of the calibrating mechanism.
*/
outb(CLK_PORT4, 0xd2);
o1 = inb(CLK_PORT1);
o1 |= inb(CLK_PORT1) << 8;
asm_fake_loop(LOOPS);
outb(CLK_PORT4, 0xd2);
o2 = inb(CLK_PORT1);
o2 |= inb(CLK_PORT1) << 8;
CPU->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) + (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0);
clk1 = rdtsc();
delay(1<<SHIFT);
clk2 = rdtsc();
CPU->frequency_mhz = (clk2-clk1)>>SHIFT;
return;
}
void i8254_interrupt(__u8 n, __native stack[])
{
trap_virtual_eoi();
}