How to export pwm class for duration, frequency, etc. settings


I have ccimx6ulsbc development board. I want to access settings for pwm5, such as duration and frequency, etc. But I found that pwm5 settings only related to the clock under /sys/kernel/debug/clk/pwm5.
I cannot export /sys/class/pwm/pwmchip0/export for accessing settings (enable, duty_cycle, period). What so I have to do in order to export pwm5 control?

Thank you,

What hardware are you using?

Assuming you are using cc6ul (SBC? Starter?) have you followed this document?
What exactly did you do to enable pwm5 in device tree?