What: /sys/class/pwm/ Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: The pwm/ class sub-directory belongs to the Generic PWM Framework and provides a sysfs interface for using PWM channels. What: /sys/class/pwm/pwmchipN/ Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: A /sys/class/pwm/pwmchipN directory is created for each probed PWM controller/chip where N is the base of the PWM chip. What: /sys/class/pwm/pwmchipN/npwm Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: The number of PWM channels supported by the PWM chip. What: /sys/class/pwm/pwmchipN/export Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: Exports a PWM channel from the PWM chip for sysfs control. Value is between 0 and /sys/class/pwm/pwmchipN/npwm - 1. What: /sys/class/pwm/pwmchipN/unexport Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: Unexports a PWM channel. What: /sys/class/pwm/pwmchipN/pwmX Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: A /sys/class/pwm/pwmchipN/pwmX directory is created for each exported PWM channel where X is the exported PWM channel number. What: /sys/class/pwm/pwmchipN/pwmX/period Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: Sets the PWM signal period in nanoseconds. What: /sys/class/pwm/pwmchipN/pwmX/duty_cycle Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: Sets the PWM signal duty cycle in nanoseconds. What: /sys/class/pwm/pwmchipN/pwmX/polarity Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: Sets the output polarity of the PWM signal to "normal" or "inversed". What: /sys/class/pwm/pwmchipN/pwmX/enable Date: May 2013 KernelVersion: 3.11 Contact: H Hartley Sweeten <hsweeten@visionengravers.com> Description: Enable/disable the PWM signal. 0 is disabled 1 is enabled What: /sys/class/pwm/pwmchipN/pwmX/capture Date: June 2016 KernelVersion: 4.8 Contact: Lee Jones <lee.jones@linaro.org> Description: Capture information about a PWM signal. The output format is a pair unsigned integers (period and duty cycle), separated by a single space.