freebsd-skq/usr.sbin/pwm/pwm.8
Emmanuel Vadot 9312900f6d Add a pwm subsystem so we can configure pwm controller from kernel and userland.
The pwm subsystem consist of API for PWM controllers, pwmbus to register them
and a pwm(8) utility to talk to them from userland.

Reviewed by:	oshgobo (capsicum), bcr (manpage), 0mp (manpage)
Differential Revision:	https://reviews.freebsd.org/D17938
2018-12-12 20:56:56 +00:00

97 lines
2.5 KiB
Groff

.\" Copyright (c) 2018 Emmanuel Vadot <manu@freebsd.org>
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd November 12, 2018
.Dt PWM 8
.Os
.Sh NAME
.Nm pwm
.Nd configure pwm controller
.Sh SYNOPSIS
.Nm
.Op Fl f Ar device
.Fl c Ar channel
.Fl E
.Nm
.Op Fl f Ar device
.Fl c Ar channel
.Fl D
.Nm
.Op Fl f Ar device
.Fl c Ar channel
.Fl C
.Nm
.Op Fl f Ar device
.Fl c Ar channel
.Fl p period
.Nm
.Op Fl f Ar device
.Fl c Ar channel
.Fl d duty
.Sh DESCRIPTION
The
.Nm
utility can be used to configure pwm controllers.
.Pp
The options are as follow:
.Bl -tag -width ".Fl f Ar device"
.It Fl c Ar channel
Channel number to operate on
.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) of the pwm channel
.El
.Sh EXAMPLES
.Bl -bullet
.It
Show the configuration of the pwm channel:
.Pp
pwm -f /dev/pwmc0 -C
.It
Configure a 50000 ns period and a 25000 duty cycles:
.Pp
pwm -f /dev/pwmc0 -p 50000 -d 25000
.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 .