【Linux设备驱动程序（第三版）】----获取当前时间_linux 驱动中获取当前时间-优快云博客

本文链接：https://blog.youkuaiyun.com/wzz_momo/article/details/6592444

本文介绍了一种在Linux设备驱动程序中获取当前时间的方法，通过使用`jiffies`、`get_jiffies_64()`、`do_gettimeofday()`等函数，实现了将时间以十六进制和浮点数格式输出到`/proc`目录下的`jit_currentime`文件中。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

【Linux设备驱动程序（第三版）】----获取当前时间

jit.c

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <asm/hardirq.h>
#include <linux/sched.h>//jiffies
#include <linux/kernel.h>
#include <linux/types.h>//u64
#include <linux/fs.h>//file_operations, file
#include <linux/completion.h>
#include <asm/uaccess.h>//copy_to_user & copy_from_user

int jit_currentime(char *buf, char **start, off_t offset, int len, int *eof, void *data)
{
	struct timeval tv1;
	struct timespec tv2;
	unsigned long j1;
	u64 j2;

	j1 = jiffies;
	j2 = get_jiffies_64();
	do_gettimeofday(&tv1);
	tv2 = current_kernel_time();
	
	len = 0;
	len += sprintf(buf,"0x%08lx 0x%016Lx %10i.%06i\n"
		       "%40i.%09i\n",
		       j1, j2,
		       (int) tv1.tv_sec, (int) tv1.tv_usec,
		       (int) tv2.tv_sec, (int) tv2.tv_nsec);
	*start = buf;
	return len;
}

int __init jit_init(void)
{
	printk(KERN_DEBUG "jit_init......");
	create_proc_read_entry("jit_currentime", 0, NULL, jit_currentime, NULL);
	return 0;
}

void __exit jit_exit(void)
{
	remove_proc_entry("jit_currentime", NULL);
}

MODULE_LICENSE("Dual BSD/GPL");
module_init(jit_init);
module_exit(jit_exit);

Makefile

obj-m:= jit.o
modules-objs:= jit.o

KDIR:= /usr/src/linux-headers-2.6.31-14-generic/
PWD:= $(shell pwd)

default:
 make -C $(KDIR) M=$(PWD) modules
clean:
 rm -rf *.ko *.mod.c *.mod.o *.o *.markers *.symvers *.order

装载驱动

insmod jit.ko

测试

cat /proc/jit_currentime

输出结果：

0x000d52fd 0x00000001000d52fd 1310097626.455468
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455470
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455472
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455474
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455476
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455478
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455481
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455483
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455485
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455487
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455489
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455491
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455493
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455495
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455497
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455499
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455502
                              1310097626.454516548
0x000d52fd 0x00000001000d52fd 1310097626.455504
                              1310097626.454516548