rt-thread/bsp/cvitek/c906_little/board/tick.c

64 lines
1.4 KiB
C
Executable File

/*
* Copyright (c) 2006-2024, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2024/01/11 flyingcys The first version
*/
#include <rthw.h>
#include <rtthread.h>
#include <encoding.h>
#include "tick.h"
static volatile rt_uint64_t time_elapsed = 0;
static volatile unsigned long tick_cycles = 0;
#define CLINT_BASE (PLIC_PHY_ADDR + 0x4000000UL)
static volatile rt_uint32_t *mtimecmp_l = (volatile rt_uint32_t *)(CLINT_BASE + 0x4000UL);
static volatile rt_uint32_t *mtimecmp_h = (volatile rt_uint32_t *)(CLINT_BASE + 0x4004UL);
rt_inline void set_ticks(rt_uint64_t value)
{
*mtimecmp_l = 0xFFFFFFFF;
*mtimecmp_h = (rt_uint32_t)(value >> 32);
*mtimecmp_l = (rt_uint32_t)(value & 0xFFFFFFFF);
}
static rt_uint64_t get_ticks(void)
{
__asm__ __volatile__(
"rdtime %0"
: "=r"(time_elapsed));
return time_elapsed;
}
int rt_hw_tick_isr(void)
{
rt_tick_increase();
set_ticks(get_ticks() + tick_cycles);
return 0;
}
/* Sets and enable the timer interrupt */
int rt_hw_tick_init(void)
{
/* Clear the Machine-Timer bit in MIE */
clear_csr(mie, MIP_MTIP);
tick_cycles = TIMER_CLK_FREQ / RT_TICK_PER_SECOND;
set_ticks(get_ticks() + tick_cycles);
rt_kprintf("[rt_hw_tick_init] time_elapsed: %d tick_cycles:%d\n", time_elapsed, tick_cycles);
/* Enable the Machine-Timer bit in MIE */
set_csr(mie, MIP_MTIP);
return 0;
}