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