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|---|
| /* |
| * 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; |
| |
| |
| the->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(); |
| |
| the->cpu->frequency_mhz = (clk2-clk1)>>SHIFT; |
| |
| return; |
| } |
| |
| void i8254_interrupt(__u8 n, __u32 stack[]) |
| { |
| trap_virtual_eoi(); |
| clock(); |
| } |