Linux内核驱动定时微秒级别实现

Linux内核驱动定时微秒级别实现

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#include <linux/module.h>


#include <linux/kthread.h>


#define TIMEOUT_HR 1000000  /* 1us */
static struct hrtimer etx_hr_timer;
ktime_t ktime;


enum hrtimer_restart hrtimer_callback(struct hrtimer *timer)
{
    static int count;

    printk(KERN_INFO "hrtimer callback is running count:%d\n", count++);
    hrtimer_forward_now(timer, ktime_set(0, TIMEOUT_HR));

    return HRTIMER_RESTART;
}
static int  __init lkm_init(void)
{
    printk(KERN_INFO "init lkm module.\n");

    /* 设置高精度时钟 */
    ktime = ktime_set(0, TIMEOUT_HR);
    hrtimer_init(&etx_hr_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
    etx_hr_timer.function = &hrtimer_callback;
    hrtimer_start(&etx_hr_timer, ktime, HRTIMER_MODE_REL);

    return 0;

}

static void __exit lkm_exit(void)
{

    hrtimer_cancel(&etx_hr_timer);

    printk(KERN_INFO "exit lkm module.\n");
}

module_init(lkm_init);
module_exit(lkm_exit);

MODULE_VERSION("0.0");
MODULE_DESCRIPTION("sample kernel module");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("liweijie");

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