0,0 → 1,162 |
/* |
* 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. |
*/ |
|
/** @addtogroup ia32 |
* @{ |
*/ |
/** |
* @file |
* @brief i8254 chip driver. |
* |
* Low level time functions. |
*/ |
|
#include <arch/types.h> |
#include <time/clock.h> |
#include <time/delay.h> |
#include <arch/cycle.h> |
#include <arch/interrupt.h> |
#include <arch/drivers/i8259.h> |
#include <arch/drivers/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> |
#include <ddi/irq.h> |
#include <ddi/device.h> |
|
#define CLK_PORT1 0x40 |
#define CLK_PORT4 0x43 |
|
#define CLK_CONST 1193180 |
#define MAGIC_NUMBER 1194 |
|
static irq_t i8254_irq; |
|
static irq_ownership_t i8254_claim(void) |
{ |
return IRQ_ACCEPT; |
} |
|
static void i8254_irq_handler(irq_t *irq, void *arg __attribute__((unused)), ...) |
{ |
/* |
* This IRQ is responsible for kernel preemption. |
* Nevertheless, we are now holding a spinlock which prevents |
* preemption. For this particular IRQ, we don't need the |
* lock. We just release it, call clock() and then reacquire it again. |
*/ |
spinlock_unlock(&irq->lock); |
clock(); |
spinlock_lock(&irq->lock); |
} |
|
void i8254_init(void) |
{ |
irq_initialize(&i8254_irq); |
i8254_irq.preack = true; |
i8254_irq.devno = device_assign_devno(); |
i8254_irq.inr = IRQ_CLK; |
i8254_irq.claim = i8254_claim; |
i8254_irq.handler = i8254_irq_handler; |
irq_register(&i8254_irq); |
|
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); |
} |
|
#define LOOPS 150000 |
#define SHIFT 11 |
void i8254_calibrate_delay_loop(void) |
{ |
uint64_t clk1, clk2; |
uint32_t t1, t2, o1, o2; |
uint8_t 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 = (uint8_t) ((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 = get_cycle(); |
delay(1 << SHIFT); |
clk2 = get_cycle(); |
|
CPU->frequency_mhz = (clk2 - clk1) >> SHIFT; |
|
return; |
} |
|
/** @} |
*/ |