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/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2018/10/28 Bernard The unify RISC-V porting code.
* 2024/07/08 Shell Using clock_time as tick
*/
#include <rthw.h>
#include <rtthread.h>
#include <encoding.h>
#include "sbi.h"
#ifdef RT_USING_CLOCK_TIME
#include <drivers/clock_time.h>
#endif
static volatile unsigned long tick_cycles = 0;
static rt_uint64_t _clock_timer_freq = 0;
rt_weak rt_uint64_t rt_hw_get_clock_timer_freq(void)
{
return CLOCK_TIMER_FREQ;
}
static rt_uint64_t _riscv_read_time(void)
{
unsigned long time_elapsed;
__asm__ __volatile__("rdtime %0" : "=r"(time_elapsed));
return (rt_uint64_t)time_elapsed;
}
int tick_isr(void)
{
rt_tick_increase();
sbi_set_timer(_riscv_read_time() + tick_cycles);
return 0;
}
/* Sets and enable the timer interrupt */
int rt_hw_tick_init(void)
{
rt_uint64_t freq = rt_hw_get_clock_timer_freq();
RT_ASSERT(freq != 0);
_clock_timer_freq = freq;
/* calculate the tick cycles */
tick_cycles = freq / RT_TICK_PER_SECOND;
/* Clear the Supervisor-Timer bit in SIE */
clear_csr(sie, SIP_STIP);
/* Set timer */
sbi_set_timer(_riscv_read_time() + tick_cycles);
#ifdef RT_USING_CLOCK_TIME
rt_clock_time_source_init();
#endif
/* Enable the Supervisor-Timer bit in SIE */
set_csr(sie, SIP_STIP);
return 0;
}
/**
* This function will delay for some us.
*
* @param us the delay time of us
*/
void rt_hw_us_delay(rt_uint32_t us)
{
unsigned long start_time;
unsigned long end_time;
unsigned long run_time;
rt_uint64_t freq;
start_time = _riscv_read_time();
freq = _clock_timer_freq ? _clock_timer_freq : rt_hw_get_clock_timer_freq();
RT_ASSERT(freq != 0);
end_time = start_time + (rt_uint64_t)us * freq / 1000000ULL;
do
{
run_time = _riscv_read_time();
} while(run_time < end_time);
}
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