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PWM(8) FreeBSD System Manager's Manual PWM(8) NAME pwm - configure PWM (Pulse Width Modulation) hardware SYNOPSIS pwm [-f device] -C pwm [-f device] [-D | -E] [-I] [-p period] [-d duty] DESCRIPTION The pwm utility can be used to configure pwm hardware. pwm uses a pwmc(4) device to communicate with the hardware. Some PWM hardware supports multiple output channels within a single controller block; each pwmc(4) instance controls a single PWM channel. pwmc(4) devices are named /dev/pwm/pwmcX.Y, where X is the controller unit number and Y is the channel number within that unit. The options are as follows: -f device Device to operate on. If not specified, /dev/pwm/pwmc0.0 is used. If an unqualified name is provided, /dev/pwm is automatically prepended. -C Show the configuration of the PWM channel. -D Disable the PWM channel. -d duty Configure the duty cycle (in nanoseconds or percentage) of the PWM channel. Duty is the portion of the period during which the signal is asserted. -E Enable the PWM channel. -p period Configure the period (in nanoseconds) of the PWM channel. -I Invert PWM signal polarity EXAMPLES o Show the configuration of the PWM channel: pwm -f /dev/pwm/pwmc0.1 -C o Configure a 50000 ns period and a 25000 ns duty cycle and enable the channel: pwm -f pwmc1.1 -E -p 50000 -d 25000 o Configure a 50% duty cycle on the device and channel which were configured in pwmc(4) to have the label backlight: pwm -f backlight -d 50% SEE ALSO pwm(9), pwmbus(9) HISTORY The pwm utility appeared in FreeBSD 13.0.