coreboot-libre-fam15h-rdimm/3rdparty/chromeec/chip/mec1322/hwtimer.c

110 lines
2.5 KiB
C

/* Copyright 2013 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Hardware timers driver */
#include "clock.h"
#include "common.h"
#include "hooks.h"
#include "hwtimer.h"
#include "registers.h"
#include "task.h"
#include "timer.h"
void __hw_clock_event_set(uint32_t deadline)
{
MEC1322_TMR32_CNT(1) = MEC1322_TMR32_CNT(0) -
(0xffffffff - deadline);
MEC1322_TMR32_CTL(1) |= BIT(5);
}
uint32_t __hw_clock_event_get(void)
{
return MEC1322_TMR32_CNT(1) - MEC1322_TMR32_CNT(0) + 0xffffffff;
}
void __hw_clock_event_clear(void)
{
MEC1322_TMR32_CTL(1) &= ~BIT(5);
}
uint32_t __hw_clock_source_read(void)
{
return 0xffffffff - MEC1322_TMR32_CNT(0);
}
void __hw_clock_source_set(uint32_t ts)
{
MEC1322_TMR32_CTL(0) &= ~BIT(5);
MEC1322_TMR32_CNT(0) = 0xffffffff - ts;
MEC1322_TMR32_CTL(0) |= BIT(5);
}
static void __hw_clock_source_irq(int timer_id)
{
if (timer_id == 1)
MEC1322_TMR32_STS(1) |= 1;
/* If IRQ is from timer 0, 32-bit timer overflowed */
process_timers(timer_id == 0);
}
void __hw_clock_source_irq_0(void) { __hw_clock_source_irq(0); }
DECLARE_IRQ(MEC1322_IRQ_TIMER32_0, __hw_clock_source_irq_0, 1);
void __hw_clock_source_irq_1(void) { __hw_clock_source_irq(1); }
DECLARE_IRQ(MEC1322_IRQ_TIMER32_1, __hw_clock_source_irq_1, 1);
static void configure_timer(int timer_id)
{
uint32_t val;
/* Ensure timer is not running */
MEC1322_TMR32_CTL(timer_id) &= ~BIT(5);
/* Enable timer */
MEC1322_TMR32_CTL(timer_id) |= BIT(0);
val = MEC1322_TMR32_CTL(timer_id);
/* Pre-scale = 48 -> 1MHz -> Period = 1us */
val = (val & 0xffff) | (47 << 16);
MEC1322_TMR32_CTL(timer_id) = val;
/* Set preload to use the full 32 bits of the timer */
MEC1322_TMR32_PRE(timer_id) = 0xffffffff;
/* Enable interrupt */
MEC1322_TMR32_IEN(timer_id) |= 1;
}
int __hw_clock_source_init(uint32_t start_t)
{
/*
* The timer can only fire interrupt when its value reaches zero.
* Therefore we need two timers:
* - Timer 0 as free running timer
* - Timer 1 as event timer
*/
configure_timer(0);
configure_timer(1);
/* Override the count */
MEC1322_TMR32_CNT(0) = 0xffffffff - start_t;
/* Auto restart */
MEC1322_TMR32_CTL(0) |= BIT(3);
/* Start counting in timer 0 */
MEC1322_TMR32_CTL(0) |= BIT(5);
/* Enable interrupt */
task_enable_irq(MEC1322_IRQ_TIMER32_0);
task_enable_irq(MEC1322_IRQ_TIMER32_1);
MEC1322_INT_ENABLE(23) |= BIT(4) | BIT(5);
MEC1322_INT_BLK_EN |= BIT(23);
return MEC1322_IRQ_TIMER32_1;
}