| 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 |