0,0 → 1,127 |
/* |
* 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.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); |
trap_virtual_disable_irqs(1<<IRQ_CLK); |
outb(CLK_PORT1, (CLK_CONST/HZ) & 0xf); |
outb(CLK_PORT1, (CLK_CONST/HZ) >> 8); |
trap_virtual_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, __u32 stack[]) |
{ |
trap_virtual_eoi(); |
clock(); |
} |