2026-01-21 18:59:54 +08:00
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What: /sys/class/pwm/
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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The pwm/ class sub-directory belongs to the Generic PWM
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Framework and provides a sysfs interface for using PWM
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channels.
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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A /sys/class/pwm/pwmchipN directory is created for each
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probed PWM controller/chip where N is the base of the
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PWM chip.
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/npwm
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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The number of PWM channels supported by the PWM chip.
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/export
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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Exports a PWM channel from the PWM chip for sysfs control.
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Value is between 0 and /sys/class/pwm/pwmchipN/npwm - 1.
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/unexport
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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Unexports a PWM channel.
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/pwmX
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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A /sys/class/pwm/pwmchipN/pwmX directory is created for
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each exported PWM channel where X is the exported PWM
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channel number.
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/pwmX/period
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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Sets the PWM signal period in nanoseconds.
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/pwmX/duty_cycle
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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Sets the PWM signal duty cycle in nanoseconds.
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/pwmX/polarity
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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Sets the output polarity of the PWM signal to "normal" or
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"inversed".
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/pwmX/enable
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2026-01-21 18:59:54 +08:00
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Date: May 2013
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KernelVersion: 3.11
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Contact: H Hartley Sweeten <hsweeten@visionengravers.com>
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Description:
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Enable/disable the PWM signal.
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0 is disabled
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1 is enabled
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2026-01-29 22:25:33 +08:00
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What: /sys/class/pwm/pwmchip<N>/pwmX/capture
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2026-01-21 18:59:54 +08:00
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Date: June 2016
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KernelVersion: 4.8
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2026-01-29 22:25:33 +08:00
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Contact: Lee Jones <lee@kernel.org>
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2026-01-21 18:59:54 +08:00
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Description:
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Capture information about a PWM signal. The output format is a
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pair unsigned integers (period and duty cycle), separated by a
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single space.
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