Documentation/ABI/testing/sysfs-class-pwm

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-class-pwm

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-class-pwm
Extension
[no extension]
Size
2578 bytes
Lines
89
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

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/pwmchip<N>/
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/pwmchip<N>/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/pwmchip<N>/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/pwmchip<N>/unexport
Date:		May 2013
KernelVersion:	3.11
Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
Description:
		Unexports a PWM channel.

What:		/sys/class/pwm/pwmchip<N>/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/pwmchip<N>/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/pwmchip<N>/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/pwmchip<N>/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".

Annotation

Implementation Notes