root@f2k-kali:/mnt/switch10-17-16$ tree /sys/class/pwm/pwmchip0/
device/    export     npwm       power/     subsystem/ uevent     unexport   
root@f2k-kali:/mnt/switch10-17-16$ tree /sys/class/pwm/pwmchip0/
/sys/class/pwm/pwmchip0/
├── device -> ../../../crystal_cove_pwm
├── export
├── npwm
├── power
│   ├── async
│   ├── autosuspend_delay_ms
│   ├── control
│   ├── runtime_active_kids
│   ├── runtime_active_time
│   ├── runtime_enabled
│   ├── runtime_status
│   ├── runtime_suspended_time
│   └── runtime_usage
├── subsystem -> ../../../../../../../../class/pwm
├── uevent
└── unexport

3 directories, 13 files
root@f2k-kali:/mnt/switch10-17-16$ cat /sys/class/pwm/pwmchip0/npwm 
1
root@f2k-kali:/mnt/switch10-17-16$ echo 0 > /sys/class/pwm/pwmchip0/export 
root@f2k-kali:/mnt/switch10-17-16$ tree /sys/class/pwm/pwmchip0/
/sys/class/pwm/pwmchip0/
├── device -> ../../../crystal_cove_pwm
├── export
├── npwm
├── power
│   ├── async
│   ├── autosuspend_delay_ms
│   ├── control
│   ├── runtime_active_kids
│   ├── runtime_active_time
│   ├── runtime_enabled
│   ├── runtime_status
│   ├── runtime_suspended_time
│   └── runtime_usage
├── pwm0
│   ├── capture
│   ├── duty_cycle
│   ├── enable
│   ├── period
│   ├── polarity
│   ├── power
│   │   ├── async
│   │   ├── autosuspend_delay_ms
│   │   ├── control
│   │   ├── runtime_active_kids
│   │   ├── runtime_active_time
│   │   ├── runtime_enabled
│   │   ├── runtime_status
│   │   ├── runtime_suspended_time
│   │   └── runtime_usage
│   └── uevent
├── subsystem -> ../../../../../../../../class/pwm
├── uevent
└── unexport

5 directories, 28 files
root@f2k-kali:/mnt/switch10-17-16$ cat /sys/class/pwm/pwmchip0/p
power/ pwm0/  
root@f2k-kali:/mnt/switch10-17-16$ cat /sys/class/pwm/pwmchip0/p
power/ pwm0/  
root@f2k-kali:/mnt/switch10-17-16$ cat /sys/class/pwm/pwmchip0/pwm0/
capture     duty_cycle  enable      period      polarity    power/      uevent      
root@f2k-kali:/mnt/switch10-17-16$ cat /sys/class/pwm/pwmchip0/pwm0/*
cat: /sys/class/pwm/pwmchip0/pwm0/capture: Function not implemented
0
0
0
normal
cat: /sys/class/pwm/pwmchip0/pwm0/power: Is a directory
root@f2k-kali:/mnt/switch10-17-16$ echo 50 > /sys/class/pwm/pwmchip0/pwm0/duty_cycle 
root@f2k-kali:/mnt/switch10-17-16$ echo 100 > /sys/class/pwm/pwmchip0/pwm0/period 
root@f2k-kali:/mnt/switch10-17-16$ echo 1 > /sys/class/pwm/pwmchip0/pwm0/enable
root@f2k-kali:/mnt/switch10-17-16$ cat /sys/class/pwm/pwmchip0/pwm0/*
cat: /sys/class/pwm/pwmchip0/pwm0/capture: Function not implemented
50
1
100
normal
cat: /sys/class/pwm/pwmchip0/pwm0/power: Is a directory
root@f2k-kali:/mnt/switch10-17-16$ exit
Script done, file is pwm_fun.script