led_test.c

来自「一个简单的字符设备的驱动--led的驱动,对于学习linux驱动有一定的帮助!」· C语言 代码 · 共 35 行

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/delay.h>
#include <linux/fcntl.h>
#include <linux/kernel.h>


int main(int argc, char** argv)

{	int fd;
	unsigned char i = 0;
	unsigned char status;

	fd = open("/dev/led",O_RDWR);
	if(fd < 0)
	{
		printf("Can't open the matrix led drivers!\n");
		return fd;
	}

	while(1)
	{
		i = (i+1)&0x0F;
		write(fd,&i,1);
		if(read(fd,&status,1) != 0)
			printf("led status: %02x\n",status);
		msleep(100*1000);
	
	}	
	close(fd);	
	return 0;	
}