code: func (p *PWMPin) DutyCycle() (duty uint32, err error) {
  	buf, err := p.read(p.pwmDutyCyclePath())
  	if err != nil {
  		return
  	}
  
  	val, e := strconv.Atoi(string(buf))
  	return uint32(val), e
  }
docs: // DutyCycle reads from pwm duty cycle path and returns value in nanoseconds