zephyr/drivers/timer/xtensa_sys_timer.c

125 lines
2.5 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>
#define TIMER_IRQ UTIL_CAT(XCHAL_TIMER, \
UTIL_CAT(CONFIG_XTENSA_TIMER_ID, _INTERRUPT))
#define CYC_PER_TICK (sys_clock_hw_cycles_per_sec() \
/ CONFIG_SYS_CLOCK_TICKS_PER_SEC)
#define MAX_CYC 0xffffffffu
#define MAX_TICKS ((MAX_CYC - CYC_PER_TICK) / CYC_PER_TICK)
#define MIN_DELAY 1000
static struct k_spinlock lock;
static unsigned int last_count;
static void set_ccompare(uint32_t val)
{
__asm__ volatile ("wsr.CCOMPARE" STRINGIFY(CONFIG_XTENSA_TIMER_ID) " %0"
:: "r"(val));
}
static uint32_t ccount(void)
{
uint32_t val;
__asm__ volatile ("rsr.CCOUNT %0" : "=r"(val));
return val;
}
static void ccompare_isr(const void *arg)
{
ARG_UNUSED(arg);
k_spinlock_key_t key = k_spin_lock(&lock);
uint32_t curr = ccount();
uint32_t dticks = (curr - last_count) / CYC_PER_TICK;
last_count += dticks * CYC_PER_TICK;
if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
uint32_t next = last_count + CYC_PER_TICK;
if ((int32_t)(next - curr) < MIN_DELAY) {
next += CYC_PER_TICK;
}
set_ccompare(next);
}
k_spin_unlock(&lock, key);
sys_clock_announce(IS_ENABLED(CONFIG_TICKLESS_KERNEL) ? dticks : 1);
}
int sys_clock_driver_init(const struct device *dev)
{
ARG_UNUSED(dev);
IRQ_CONNECT(TIMER_IRQ, 0, ccompare_isr, 0, 0);
set_ccompare(ccount() + CYC_PER_TICK);
irq_enable(TIMER_IRQ);
return 0;
}
void sys_clock_set_timeout(int32_t ticks, bool idle)
{
ARG_UNUSED(idle);
#if defined(CONFIG_TICKLESS_KERNEL)
ticks = ticks == K_TICKS_FOREVER ? MAX_TICKS : ticks;
ticks = CLAMP(ticks - 1, 0, (int32_t)MAX_TICKS);
k_spinlock_key_t key = k_spin_lock(&lock);
uint32_t curr = ccount(), cyc, adj;
/* Round up to next tick boundary */
cyc = ticks * CYC_PER_TICK;
adj = (curr - last_count) + (CYC_PER_TICK - 1);
if (cyc <= MAX_CYC - adj) {
cyc += adj;
} else {
cyc = MAX_CYC;
}
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
}
uint32_t sys_clock_elapsed(void)
{
if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
return 0;
}
k_spinlock_key_t key = k_spin_lock(&lock);
uint32_t ret = (ccount() - last_count) / CYC_PER_TICK;
k_spin_unlock(&lock, key);
return ret;
}
uint32_t sys_clock_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