1What:		/sys/class/pwm/
2Date:		May 2013
3KernelVersion:	3.11
4Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
5Description:
6		The pwm/ class sub-directory belongs to the Generic PWM
7		Framework and provides a sysfs interface for using PWM
8		channels.
9
10What:		/sys/class/pwm/pwmchip<N>/
11Date:		May 2013
12KernelVersion:	3.11
13Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
14Description:
15		A /sys/class/pwm/pwmchipN directory is created for each
16		probed PWM controller/chip where N is the base of the
17		PWM chip.
18
19What:		/sys/class/pwm/pwmchip<N>/npwm
20Date:		May 2013
21KernelVersion:	3.11
22Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
23Description:
24		The number of PWM channels supported by the PWM chip.
25
26What:		/sys/class/pwm/pwmchip<N>/export
27Date:		May 2013
28KernelVersion:	3.11
29Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
30Description:
31		Exports a PWM channel from the PWM chip for sysfs control.
32		Value is between 0 and /sys/class/pwm/pwmchipN/npwm - 1.
33
34What:		/sys/class/pwm/pwmchip<N>/unexport
35Date:		May 2013
36KernelVersion:	3.11
37Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
38Description:
39		Unexports a PWM channel.
40
41What:		/sys/class/pwm/pwmchip<N>/pwmX
42Date:		May 2013
43KernelVersion:	3.11
44Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
45Description:
46		A /sys/class/pwm/pwmchipN/pwmX directory is created for
47		each exported PWM channel where X is the exported PWM
48		channel number.
49
50What:		/sys/class/pwm/pwmchip<N>/pwmX/period
51Date:		May 2013
52KernelVersion:	3.11
53Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
54Description:
55		Sets the PWM signal period in nanoseconds.
56
57What:		/sys/class/pwm/pwmchip<N>/pwmX/duty_cycle
58Date:		May 2013
59KernelVersion:	3.11
60Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
61Description:
62		Sets the PWM signal duty cycle in nanoseconds.
63
64What:		/sys/class/pwm/pwmchip<N>/pwmX/polarity
65Date:		May 2013
66KernelVersion:	3.11
67Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
68Description:
69		Sets the output polarity of the PWM signal to "normal" or
70		"inversed".
71
72What:		/sys/class/pwm/pwmchip<N>/pwmX/enable
73Date:		May 2013
74KernelVersion:	3.11
75Contact:	H Hartley Sweeten <hsweeten@visionengravers.com>
76Description:
77		Enable/disable the PWM signal.
78		0 is disabled
79		1 is enabled
80
81What:		/sys/class/pwm/pwmchip<N>/pwmX/capture
82Date:		June 2016
83KernelVersion:	4.8
84Contact:	Lee Jones <lee.jones@linaro.org>
85Description:
86		Capture information about a PWM signal. The output format is a
87		pair unsigned integers (period and duty cycle), separated by a
88		single space.
89