zephyr/drivers/timer/xtensa_sys_timer.c

129 lines
2.7 KiB
C

/*
* Copyright (c) 2018 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <drivers/timer/system_timer.h>
#include <sys_clock.h>
#include <spinlock.h>
#include <xtensa_rtos.h>
#define TIMER_IRQ UTIL_CAT(XCHAL_TIMER, \
UTIL_CAT(CONFIG_XTENSA_TIMER_ID, _INTERRUPT))
#define CYC_PER_TICK (CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC \
/ CONFIG_SYS_CLOCK_TICKS_PER_SEC)
#define MAX_TICKS ((0xffffffffu - CYC_PER_TICK) / CYC_PER_TICK)
#define MIN_DELAY 1000
static struct k_spinlock lock;
static unsigned int last_count;
static void set_ccompare(u32_t val)
{
__asm__ volatile ("wsr.CCOMPARE" STRINGIFY(CONFIG_XTENSA_TIMER_ID) " %0"
:: "r"(val));
}
static u32_t ccount(void)
{
u32_t val;
__asm__ volatile ("rsr.CCOUNT %0" : "=r"(val));
return val;
}
static void ccompare_isr(void *arg)
{
ARG_UNUSED(arg);
k_spinlock_key_t key = k_spin_lock(&lock);
u32_t curr = ccount();
u32_t dticks = (curr - last_count) / CYC_PER_TICK;
last_count += dticks * CYC_PER_TICK;
if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL) ||
IS_ENABLED(CONFIG_QEMU_TICKLESS_WORKAROUND)) {
u32_t next = last_count + CYC_PER_TICK;
if ((s32_t)(next - curr) < MIN_DELAY) {
next += CYC_PER_TICK;
}
set_ccompare(next);
}
k_spin_unlock(&lock, key);
z_clock_announce(IS_ENABLED(CONFIG_TICKLESS_KERNEL) ? dticks : 1);
}
/* The legacy Xtensa platform code handles the timer interrupt via a
* special path and must find it via this name. Remove once ASM2 is
* pervasive.
*/
#ifndef CONFIG_XTENSA_ASM2
void timer_int_handler(void *arg)
{
return ccompare_isr(arg);
}
#endif
int z_clock_driver_init(struct device *device)
{
IRQ_CONNECT(TIMER_IRQ, 0, ccompare_isr, 0, 0);
set_ccompare(ccount() + CYC_PER_TICK);
irq_enable(TIMER_IRQ);
return 0;
}
void z_clock_set_timeout(s32_t ticks, bool idle)
{
ARG_UNUSED(idle);
#if defined(CONFIG_TICKLESS_KERNEL) && !defined(CONFIG_QEMU_TICKLESS_WORKAROUND)
ticks = ticks == K_FOREVER ? MAX_TICKS : ticks;
ticks = MAX(MIN(ticks - 1, (s32_t)MAX_TICKS), 0);
k_spinlock_key_t key = k_spin_lock(&lock);
u32_t curr = ccount(), cyc;
/* Round up to next tick boundary */
cyc = ticks * CYC_PER_TICK + (curr - last_count) + (CYC_PER_TICK - 1);
cyc = (cyc / CYC_PER_TICK) * CYC_PER_TICK;
cyc += last_count;
if ((cyc - curr) < MIN_DELAY) {
cyc += CYC_PER_TICK;
}
set_ccompare(cyc);
k_spin_unlock(&lock, key);
#endif
}
u32_t z_clock_elapsed(void)
{
if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
return 0;
}
k_spinlock_key_t key = k_spin_lock(&lock);
u32_t ret = (ccount() - last_count) / CYC_PER_TICK;
k_spin_unlock(&lock, key);
return ret;
}
u32_t z_timer_cycle_get_32(void)
{
return ccount();
}
#ifdef CONFIG_SMP
void smp_timer_init(void)
{
set_ccompare(ccount() + CYC_PER_TICK);
irq_enable(TIMER_IRQ);
}
#endif