#include<stdio.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>

int main(int argc,char *argv[])
{
    int ret;
    int fd;
    ret = access("/sys/class/pwm/pwmchip1/pwm0",F_OK);
    if(ret != 0 )
    {
        fd = open("/sys/class/pwm/pwmchip1/export",O_WRONLY);
        write(fd,"0",1);
        close(fd);
    }

    fd = open("/sys/class/pwm/pwmchip1/pwm0/polarity",O_WRONLY);
    write(fd,"normal",6);
    close(fd);
    
    fd = open("/sys/class/pwm/pwmchip1/pwm0/period",O_WRONLY);
    write(fd,"1000000000",10);
    close(fd);

    fd = open("/sys/class/pwm/pwmchip1/pwm0/duty_cycle",O_WRONLY);
    write(fd,argv[1],sizeof(argv[1]));
    close(fd);

    fd = open("/sys/class/pwm/pwmchip1/pwm0/enable",O_WRONLY);
    write(fd,"1",1);
    close(fd);
    
    return 0;

}