GC24001/Common/software_timer.c

#include "GD32Sys.h"

//1秒换算成1us的倍数
#define US_PER_SECOND 1000000
//当前的时间
static int cur_second = 0;
static int cur_ms = 0;
static int reload_value = 0;
unsigned long dwTickCount = 0;

static void defaut_tick_hook(void);

static void (*systick_hook)() = defaut_tick_hook;

/**
 * 默认的1ms周期中断
 *
 * @author lxz
 *
 * @param void
 */
static void defaut_tick_hook(void)
{
}

/**
 * 定时中断，1ms
 *
 * @author LXZ (010120)
 */
void SysTick_Handler()
{
    dwTickCount++;
    if (++cur_ms >= 1000)
    {
        cur_ms = 0;
        cur_second++;
    }
    systick_hook();
}

/**
 * 设置ms中断定时器的钩子函数
 *
 * @author lxz
 *
 * @param hook
 */
void sw_tick_set_hook(void (*hook)())
{
    if (hook != 0)
    {
        systick_hook = hook;
    }
}

/**
 * 初始化定时器
 *
 * @author lxz
 *
 * @param void
 */
void sw_timer_init(int clk)
{
    reload_value = clk * 1000 - 1;
    /* setup systick timer for 1000Hz interrupts */
    if (SysTick_Config(clk * 1000U)){
        /* capture error */
        while (1){
        }
    }
    /* configure the systick handler priority */
    NVIC_SetPriority(SysTick_IRQn, 0x00U);
}

/**
 * 获取当前的定时器时间
 *
 * @author lxz
 *
 * @param timer
 */
void sw_timer_now(sw_timer_t *timer)
{
    int second;
    int us;
    int ms;

    do
    {
        ms = cur_ms;
        second = cur_second;
        us = SysTick->VAL;
    } while (ms != cur_ms);

    timer->second = second;
    timer->usec = (ms * 1000) + (reload_value - us) * 1000 / reload_value;
}

/**
 * 初始化一个定时器实体用于时间比较
 *
 * @author lxz
 *
 * @param timer object 定时实体
 * @param second   要延时的秒单位
 * @param usec    要延时的毫秒单位
 */
void sw_timer_start(sw_timer_t *timer, int sec, int usec)
{
    sw_timer_now(timer);
    sw_timer_delay(timer, sec, usec);
}
/**
 * 返回定时器是否已经计时到了
 *
 * @author lxz
 *
 * @param timer 定时器实体
 *
 * @return int
 */
int sw_timer_expire(sw_timer_t *timer)
{
    sw_timer_t now;
    sw_timer_now(&now);
    if (timer->second < now.second ||
        (timer->second == now.second && timer->usec <= now.usec))
        return 1;
    return 0;
}
/**
 * 对当关定时器进行时间延后
 *
 * @author lxz
 *
 * @param timer 定时器实体
 * @param sec  要延后的秒数
 * @param usec  要延后的微秒数
 *
 * @return int
 */
void sw_timer_delay(sw_timer_t *timer, int sec, int usec)
{

    timer->usec += usec;
    timer->second += sec + timer->usec / US_PER_SECOND;
    timer->usec %= US_PER_SECOND;
}