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1 jermar 1
/*
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 * Copyright (C) 2001-2004 Jakub Jermar
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 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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#include <arch/types.h>
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#include <time/clock.h>
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#include <time/delay.h>
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#include <arch/interrupt.h>
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#include <arch/i8259.h>
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#include <arch/i8254.h>
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#include <cpu.h>
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#include <config.h>
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#include <arch/pm.h>
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#include <arch/asm.h>
195 vana 39
#include <arch/cpuid.h>
1 jermar 40
#include <arch.h>
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#include <time/delay.h>
1 jermar 42
 
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/*
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 * i8254 chip driver.
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 * Low level time functions.
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 */
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#define CLK_PORT1   0x40
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#define CLK_PORT4   0x43
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#define CLK_CONST   1193180
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#define MAGIC_NUMBER    1194
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void i8254_init(void)
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{
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    i8254_normal_operation();
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}
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void i8254_normal_operation(void)
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{
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    outb(CLK_PORT4, 0x36);
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    trap_virtual_disable_irqs(1<<IRQ_CLK);
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    outb(CLK_PORT1, (CLK_CONST/HZ) & 0xf);
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    outb(CLK_PORT1, (CLK_CONST/HZ) >> 8);
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    trap_virtual_enable_irqs(1<<IRQ_CLK);
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    trap_register(VECTOR_CLK, i8254_interrupt);
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}
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#define LOOPS 150000
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#define SHIFT 11
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void i8254_calibrate_delay_loop(void)
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{
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    __u64 clk1, clk2;
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    __u32 t1, t2, o1, o2;
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    __u8 not_ok;
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    /*
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     * One-shot timer. Count-down from 0xffff at 1193180Hz
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     * MAGIC_NUMBER is the magic value for 1ms.
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     */
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    outb(CLK_PORT4, 0x30);
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    outb(CLK_PORT1, 0xff);
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    outb(CLK_PORT1, 0xff);
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    do {
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        /* will read both status and count */
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        outb(CLK_PORT4, 0xc2);
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        not_ok = (inb(CLK_PORT1)>>6)&1;
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        t1 = inb(CLK_PORT1);
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        t1 |= inb(CLK_PORT1) << 8;
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    } while (not_ok);
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    asm_delay_loop(LOOPS);
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    outb(CLK_PORT4, 0xd2);
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    t2 = inb(CLK_PORT1);
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    t2 |= inb(CLK_PORT1) << 8;
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    /*
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     * We want to determine the overhead of the calibrating mechanism.
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     */
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    outb(CLK_PORT4, 0xd2);
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    o1 = inb(CLK_PORT1);
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    o1 |= inb(CLK_PORT1) << 8;
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    asm_fake_loop(LOOPS);
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    outb(CLK_PORT4, 0xd2);
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    o2 = inb(CLK_PORT1);
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    o2 |= inb(CLK_PORT1) << 8;
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    CPU->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) + (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0);
1 jermar 115
 
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    clk1 = rdtsc();
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    delay(1<<SHIFT);
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    clk2 = rdtsc();
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    CPU->frequency_mhz = (clk2-clk1)>>SHIFT;
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    return;
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}
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206 palkovsky 125
void i8254_interrupt(__u8 n, __native stack[])
1 jermar 126
{
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    trap_virtual_eoi();
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    clock();
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}