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- #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;
- }
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