zephyr/drivers/timer/esp32c3_sys_timer.c

137 lines
3.2 KiB
C

/*
* Copyright (c) 2021 Espressif Systems (Shanghai) Co., Ltd.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <soc/soc_caps.h>
#include <soc/soc.h>
#include <soc/interrupt_core0_reg.h>
#include <soc/periph_defs.h>
#include <soc/system_reg.h>
#include <hal/systimer_hal.h>
#include <hal/systimer_ll.h>
#include <rom/ets_sys.h>
#include <esp_attr.h>
#include <drivers/interrupt_controller/intc_esp32c3.h>
#include <drivers/timer/system_timer.h>
#include <sys_clock.h>
#include <soc.h>
#include <device.h>
#define CYC_PER_TICK ((uint32_t)((uint64_t)sys_clock_hw_cycles_per_sec() \
/ (uint64_t)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
#define TICKLESS IS_ENABLED(CONFIG_TICKLESS_KERNEL)
static struct k_spinlock lock;
static uint64_t last_count;
static void set_systimer_alarm(uint64_t time)
{
systimer_hal_select_alarm_mode(SYSTIMER_ALARM_0, SYSTIMER_ALARM_MODE_ONESHOT);
systimer_hal_set_alarm_target(SYSTIMER_ALARM_0, time);
systimer_hal_enable_alarm_int(SYSTIMER_ALARM_0);
}
static uint64_t systimer_alarm(void)
{
return systimer_hal_get_time(SYSTIMER_COUNTER_1);
}
static void sys_timer_isr(const void *arg)
{
ARG_UNUSED(arg);
systimer_ll_clear_alarm_int(SYSTIMER_ALARM_0);
k_spinlock_key_t key = k_spin_lock(&lock);
uint64_t now = systimer_alarm();
uint32_t dticks = (uint32_t)((now - last_count) / CYC_PER_TICK);
last_count += dticks * CYC_PER_TICK;
if (!TICKLESS) {
uint64_t next = last_count + CYC_PER_TICK;
if ((int64_t)(next - now) < MIN_DELAY) {
next += CYC_PER_TICK;
}
set_systimer_alarm(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);
esp_intr_alloc(DT_IRQN(DT_NODELABEL(systimer0)),
0,
sys_timer_isr,
NULL,
NULL);
systimer_hal_init();
systimer_hal_connect_alarm_counter(SYSTIMER_ALARM_0, SYSTIMER_COUNTER_1);
systimer_hal_enable_counter(SYSTIMER_COUNTER_1);
systimer_hal_counter_can_stall_by_cpu(SYSTIMER_COUNTER_1, 0, true);
last_count = systimer_alarm();
set_systimer_alarm(last_count + CYC_PER_TICK);
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);
uint64_t now = systimer_alarm();
uint32_t adj, cyc = ticks * CYC_PER_TICK;
/* Round up to next tick boundary. */
adj = (uint32_t)(now - 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;
if ((int32_t)(cyc + last_count - now) < MIN_DELAY) {
cyc += CYC_PER_TICK;
}
set_systimer_alarm(cyc + last_count);
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 = ((uint32_t)systimer_alarm() - (uint32_t)last_count) / CYC_PER_TICK;
k_spin_unlock(&lock, key);
return ret;
}
uint32_t sys_clock_cycle_get_32(void)
{
return systimer_ll_get_counter_value_low(SYSTIMER_COUNTER_1);
}