0001 What: /sys/class/pwm/
0002 Date: May 2013
0003 KernelVersion: 3.11
0004 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0005 Description:
0006 The pwm/ class sub-directory belongs to the Generic PWM
0007 Framework and provides a sysfs interface for using PWM
0008 channels.
0009
0010 What: /sys/class/pwm/pwmchip<N>/
0011 Date: May 2013
0012 KernelVersion: 3.11
0013 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0014 Description:
0015 A /sys/class/pwm/pwmchipN directory is created for each
0016 probed PWM controller/chip where N is the base of the
0017 PWM chip.
0018
0019 What: /sys/class/pwm/pwmchip<N>/npwm
0020 Date: May 2013
0021 KernelVersion: 3.11
0022 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0023 Description:
0024 The number of PWM channels supported by the PWM chip.
0025
0026 What: /sys/class/pwm/pwmchip<N>/export
0027 Date: May 2013
0028 KernelVersion: 3.11
0029 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0030 Description:
0031 Exports a PWM channel from the PWM chip for sysfs control.
0032 Value is between 0 and /sys/class/pwm/pwmchipN/npwm - 1.
0033
0034 What: /sys/class/pwm/pwmchip<N>/unexport
0035 Date: May 2013
0036 KernelVersion: 3.11
0037 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0038 Description:
0039 Unexports a PWM channel.
0040
0041 What: /sys/class/pwm/pwmchip<N>/pwmX
0042 Date: May 2013
0043 KernelVersion: 3.11
0044 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0045 Description:
0046 A /sys/class/pwm/pwmchipN/pwmX directory is created for
0047 each exported PWM channel where X is the exported PWM
0048 channel number.
0049
0050 What: /sys/class/pwm/pwmchip<N>/pwmX/period
0051 Date: May 2013
0052 KernelVersion: 3.11
0053 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0054 Description:
0055 Sets the PWM signal period in nanoseconds.
0056
0057 What: /sys/class/pwm/pwmchip<N>/pwmX/duty_cycle
0058 Date: May 2013
0059 KernelVersion: 3.11
0060 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0061 Description:
0062 Sets the PWM signal duty cycle in nanoseconds.
0063
0064 What: /sys/class/pwm/pwmchip<N>/pwmX/polarity
0065 Date: May 2013
0066 KernelVersion: 3.11
0067 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0068 Description:
0069 Sets the output polarity of the PWM signal to "normal" or
0070 "inversed".
0071
0072 What: /sys/class/pwm/pwmchip<N>/pwmX/enable
0073 Date: May 2013
0074 KernelVersion: 3.11
0075 Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
0076 Description:
0077 Enable/disable the PWM signal.
0078 0 is disabled
0079 1 is enabled
0080
0081 What: /sys/class/pwm/pwmchip<N>/pwmX/capture
0082 Date: June 2016
0083 KernelVersion: 4.8
0084 Contact: Lee Jones <lee@kernel.org>
0085 Description:
0086 Capture information about a PWM signal. The output format is a
0087 pair unsigned integers (period and duty cycle), separated by a
0088 single space.