mirror of
https://github.com/olofk/serv.git
synced 2025-06-29 01:32:59 -04:00
125 lines
2.8 KiB
C
125 lines
2.8 KiB
C
/*
|
|
* Copyright (c) 2020 Olof Kindgren <olof.kindgren@gmail.com>
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
/*
|
|
This is basically a 32-bit version of riscv_machine_timer.c for Zephyr
|
|
*/
|
|
#include <drivers/timer/system_timer.h>
|
|
#include <sys_clock.h>
|
|
#include <spinlock.h>
|
|
#include <soc.h>
|
|
|
|
#define CYC_PER_TICK ((uint32_t)((uint32_t)sys_clock_hw_cycles_per_sec() \
|
|
/ (uint32_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 uint32_t last_count;
|
|
|
|
static ALWAYS_INLINE void set_mtimecmp(uint32_t time)
|
|
{
|
|
sys_write32(time, SERV_TIMER_BASE);
|
|
}
|
|
|
|
static ALWAYS_INLINE uint32_t mtime(void)
|
|
{
|
|
return sys_read32(SERV_TIMER_BASE);
|
|
}
|
|
|
|
static void timer_isr(void *arg)
|
|
{
|
|
ARG_UNUSED(arg);
|
|
|
|
k_spinlock_key_t key = k_spin_lock(&lock);
|
|
uint32_t now = mtime();
|
|
uint32_t dticks = ((now - last_count) / CYC_PER_TICK);
|
|
|
|
last_count += dticks * CYC_PER_TICK;
|
|
|
|
if (!TICKLESS) {
|
|
uint32_t next = last_count + CYC_PER_TICK;
|
|
|
|
if ((int32_t)(next - now) < MIN_DELAY) {
|
|
next += CYC_PER_TICK;
|
|
}
|
|
set_mtimecmp(next);
|
|
}
|
|
|
|
k_spin_unlock(&lock, key);
|
|
z_clock_announce(IS_ENABLED(CONFIG_TICKLESS_KERNEL) ? dticks : 1);
|
|
}
|
|
|
|
int z_clock_driver_init(const struct device *device)
|
|
{
|
|
ARG_UNUSED(device);
|
|
|
|
IRQ_CONNECT(RISCV_MACHINE_TIMER_IRQ, 0, timer_isr, NULL, 0);
|
|
set_mtimecmp(mtime() + (uint32_t)CYC_PER_TICK);
|
|
irq_enable(RISCV_MACHINE_TIMER_IRQ);
|
|
return 0;
|
|
}
|
|
|
|
void z_clock_set_timeout(int32_t ticks, bool idle)
|
|
{
|
|
ARG_UNUSED(idle);
|
|
|
|
#if defined(CONFIG_TICKLESS_KERNEL)
|
|
/* RISCV has no idle handler yet, so if we try to spin on the
|
|
* logic below to reset the comparator, we'll always bump it
|
|
* forward to the "next tick" due to MIN_DELAY handling and
|
|
* the interrupt will never fire! Just rely on the fact that
|
|
* the OS gave us the proper timeout already.
|
|
*/
|
|
if (idle) {
|
|
return;
|
|
}
|
|
|
|
ticks = ticks == K_TICKS_FOREVER ? MAX_TICKS : ticks;
|
|
ticks = MAX(MIN(ticks - 1, (int32_t)MAX_TICKS), 0);
|
|
|
|
k_spinlock_key_t key = k_spin_lock(&lock);
|
|
uint32_t now = mtime();
|
|
uint32_t adj, cyc = ticks * CYC_PER_TICK;
|
|
|
|
/* Round up to next tick boundary. */
|
|
adj = (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_mtimecmp(cyc + last_count);
|
|
k_spin_unlock(&lock, key);
|
|
#endif
|
|
}
|
|
|
|
uint32_t z_clock_elapsed(void)
|
|
{
|
|
if (!IS_ENABLED(CONFIG_TICKLESS_KERNEL)) {
|
|
return 0;
|
|
}
|
|
|
|
k_spinlock_key_t key = k_spin_lock(&lock);
|
|
uint32_t ret = (mtime() - last_count) / CYC_PER_TICK;
|
|
|
|
k_spin_unlock(&lock, key);
|
|
return ret;
|
|
}
|
|
|
|
uint32_t z_timer_cycle_get_32(void)
|
|
{
|
|
return mtime();
|
|
}
|