zephyr/drivers/timer/arm_arch_timer.c

110 lines
2.6 KiB
C

/*
* Copyright (c) 2019 Carlo Caione <ccaione@baylibre.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <drivers/timer/arm_arch_timer.h>
#include <drivers/timer/system_timer.h>
#include <sys_clock.h>
#include <spinlock.h>
#include <arch/cpu.h>
#define CYC_PER_TICK ((u32_t)((u64_t)sys_clock_hw_cycles_per_sec() \
/ (u64_t)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 volatile u64_t last_cycle;
static void arm_arch_timer_compare_isr(void *arg)
{
ARG_UNUSED(arg);
k_spinlock_key_t key = k_spin_lock(&lock);
u64_t curr_cycle = arm_arch_timer_count();
u32_t delta_ticks = (u32_t)((curr_cycle - last_cycle) / CYC_PER_TICK);
last_cycle += delta_ticks * CYC_PER_TICK;
if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL) ||
IS_ENABLED(CONFIG_QEMU_TICKLESS_WORKAROUND)) {
u64_t next_cycle = last_cycle + CYC_PER_TICK;
if ((s64_t)(next_cycle - curr_cycle) < MIN_DELAY) {
next_cycle += CYC_PER_TICK;
}
arm_arch_timer_set_compare(next_cycle);
}
k_spin_unlock(&lock, key);
z_clock_announce(IS_ENABLED(CONFIG_TICKLESS_KERNEL) ? delta_ticks : 1);
}
int z_clock_driver_init(struct device *device)
{
ARG_UNUSED(device);
IRQ_CONNECT(ARM_ARCH_TIMER_IRQ, 0, arm_arch_timer_compare_isr, 0,
ARM_TIMER_FLAGS);
arm_arch_timer_set_compare(arm_arch_timer_count() + CYC_PER_TICK);
arm_arch_timer_enable(true);
irq_enable(ARM_ARCH_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)
if (idle) {
return;
}
ticks = (ticks == K_TICKS_FOREVER) ? MAX_TICKS : ticks;
ticks = MAX(MIN(ticks - 1, (s32_t)MAX_TICKS), 0);
k_spinlock_key_t key = k_spin_lock(&lock);
u64_t curr_cycle = arm_arch_timer_count();
u32_t req_cycle = ticks * CYC_PER_TICK;
/* Round up to next tick boundary */
req_cycle += (u32_t)(curr_cycle - last_cycle) + (CYC_PER_TICK - 1);
req_cycle = (req_cycle / CYC_PER_TICK) * CYC_PER_TICK;
if ((s32_t)(req_cycle + last_cycle - curr_cycle) < MIN_DELAY) {
req_cycle += CYC_PER_TICK;
}
arm_arch_timer_set_compare(req_cycle + last_cycle);
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 = ((u32_t)arm_arch_timer_count() - (u32_t)last_cycle)
/ CYC_PER_TICK;
k_spin_unlock(&lock, key);
return ret;
}
u32_t z_timer_cycle_get_32(void)
{
return (u32_t)arm_arch_timer_count();
}