freebsd-skq/usr.sbin/pwm/pwm.8
Ian Lepore 780c3de886 Remove everything related to channels from the pwmc public interface, now
that there is a pwmc(4) instance per channel and the channel number is
maintained as a driver ivar rather than being passed in from userland.
2019-06-18 00:11:00 +00:00

112 lines
2.8 KiB
Groff

.\" Copyright (c) 2018 Emmanuel Vadot <manu@freebsd.org>
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.\" $FreeBSD$
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.Dd June 17, 2019
.Dt PWM 8
.Os
.Sh NAME
.Nm pwm
.Nd configure pwm controller
.Sh SYNOPSIS
.Nm
.Op Fl f Ar device
.Fl E
.Nm
.Op Fl f Ar device
.Fl D
.Nm
.Op Fl f Ar device
.Fl C
.Nm
.Op Fl f Ar device
.Fl p Ar period
.Nm
.Op Fl f Ar device
.Fl d Ar duty
.Sh DESCRIPTION
The
.Nm
utility can be used to configure pwm controllers.
.Pp
The options are as follow:
.Bl -tag -width "-f device"
.It Fl f Ar device
Device to operate on.
If not specified,
.Pa /dev/pwm/pwmc0.0
is used.
If an unqualified name is provided,
.Pa /dev/pwm
is automatically prepended.
.It Fl E
Enable the pwm channel.
.It Fl D
Disable the pwm channel.
.It Fl C
Show the configuration of the pwm channel.
.It Fl p Ar period
Configure the period (in nanoseconds) of the pwm channel
.It Fl d Ar duty
Configure the duty (in nanoseconds or percentage) of the pwm channel.
Duty is the portion of the
.Ar period
during which the signal is asserted.
.El
.Sh EXAMPLES
.Bl -bullet
.It
Show the configuration of the pwm channel:
.Bd -literal
pwm -f /dev/pwm/pwmc0.1 -C
.Ed
.It
Configure a 50000 ns period and a 25000 ns duty cycle:
.Bd -literal
pwm -f pwmc1.1 -p 50000 -d 25000
.Ed
.It
Configure a 50% duty cycle on the device and channel which
were configured in
.Xr pwmc 4
to have the label
.Pa backlight :
.Bd -literal
pwm -f backlight -d 50%
.Ed
.El
.Sh SEE ALSO
.Xr pwm 9 ,
.Xr pwmbus 9
.Sh HISTORY
The
.Nm
utility appeared in
.Fx 13.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
utility and this manual page were written by
.An Emmanuel Vadot Aq Mt manu@FreeBSD.org .