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freebsd-dev/usr.sbin/pwm/pwm.8

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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
.\" 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.
.\"
.\" $FreeBSD$
.\"
Follow changes in the pwmc(4) driver in relation to device filenames. The driver now names its cdev nodes pwmcX.Y where X is unit number and Y is the channel within that unit. Change the default device name from pwmc0 to pwmc0.0. The driver now puts cdev files and label aliases in the /dev/pwm directory, so allow the user to provide unqualified names with -f and automatically prepend the /dev/pwm part for them. Update the examples in the manpage to show the new device name format and location within /dev/pwm.
2019-06-17 16:43:33 +00:00
.Dd June 17, 2019
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
.Dt PWM 8
.Os
.Sh NAME
.Nm pwm
Explain the relationship between PWM hardware channels being controlled and pwmc(4) device filenames. Also, use uppercase PWM when the term is being used as an acronym, and expand the acronym where it's first used.
2019-06-18 00:17:10 +00:00
.Nd configure PWM (Pulse Width Modulation) hardware
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
.Sh SYNOPSIS
.Nm
.Op Fl f Ar device
.Fl C
.Nm
.Op Fl f Ar device
Rearrange the argument checking and processing so that enable and disable can be combined with configuring the period and duty cycle (the same ioctl sets all 3 values at once, so there's no reason to require the user to run the program twice to get all 3 things set).
2019-06-18 01:15:00 +00:00
.Op Fl D | Fl E
.Op Fl p Ar period
.Op Fl d Ar duty
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
.Sh DESCRIPTION
The
.Nm
Explain the relationship between PWM hardware channels being controlled and pwmc(4) device filenames. Also, use uppercase PWM when the term is being used as an acronym, and expand the acronym where it's first used.
2019-06-18 00:17:10 +00:00
utility can be used to configure pwm hardware.
.Nm
uses a
.Xr pwmc 4
device to communicate with the hardware.
Some PWM hardware supports multiple output channels within a single
controller block; each
.Xr pwmc 4
instance controls a single PWM channel.
.Pp
.Xr pwmc 4
devices are named
.Pa /dev/pwm/pwmcX.Y ,
where
.Va X
is the controller unit number and
.Va Y
is the channel number within that unit.
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
.Pp
Explain the relationship between PWM hardware channels being controlled and pwmc(4) device filenames. Also, use uppercase PWM when the term is being used as an acronym, and expand the acronym where it's first used.
2019-06-18 00:17:10 +00:00
The options are as follows:
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
.Bl -tag -width "-f device"
pwm.8: fix markup in synopsis, add -f description Reviewed by: bcr, manu Differential revision: https://reviews.freebsd.org/D18829
2019-02-06 04:00:37 +00:00
.It Fl f Ar device
Device to operate on.
If not specified,
Follow changes in the pwmc(4) driver in relation to device filenames. The driver now names its cdev nodes pwmcX.Y where X is unit number and Y is the channel within that unit. Change the default device name from pwmc0 to pwmc0.0. The driver now puts cdev files and label aliases in the /dev/pwm directory, so allow the user to provide unqualified names with -f and automatically prepend the /dev/pwm part for them. Update the examples in the manpage to show the new device name format and location within /dev/pwm.
2019-06-17 16:43:33 +00:00
.Pa /dev/pwm/pwmc0.0
pwm.8: fix markup in synopsis, add -f description Reviewed by: bcr, manu Differential revision: https://reviews.freebsd.org/D18829
2019-02-06 04:00:37 +00:00
is used.
Follow changes in the pwmc(4) driver in relation to device filenames. The driver now names its cdev nodes pwmcX.Y where X is unit number and Y is the channel within that unit. Change the default device name from pwmc0 to pwmc0.0. The driver now puts cdev files and label aliases in the /dev/pwm directory, so allow the user to provide unqualified names with -f and automatically prepend the /dev/pwm part for them. Update the examples in the manpage to show the new device name format and location within /dev/pwm.
2019-06-17 16:43:33 +00:00
If an unqualified name is provided,
.Pa /dev/pwm
is automatically prepended.
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
.It Fl C
Explain the relationship between PWM hardware channels being controlled and pwmc(4) device filenames. Also, use uppercase PWM when the term is being used as an acronym, and expand the acronym where it's first used.
2019-06-18 00:17:10 +00:00
Show the configuration of the PWM channel.
Rearrange the argument checking and processing so that enable and disable can be combined with configuring the period and duty cycle (the same ioctl sets all 3 values at once, so there's no reason to require the user to run the program twice to get all 3 things set).
2019-06-18 01:15:00 +00:00
.It Fl D
Disable the PWM channel.
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
.It Fl d Ar duty
Oops, it seems I left out the word 'cycle', fix it. Reported by: rpokala@
2019-06-18 02:27:30 +00:00
Configure the duty cycle (in nanoseconds or percentage) of the PWM channel.
Put periods at the ends of argument descriptions. Explain the relationship between the period and duty arguments.
2019-06-17 16:50:58 +00:00
Duty is the portion of the
.Ar period
during which the signal is asserted.
Rearrange the argument checking and processing so that enable and disable can be combined with configuring the period and duty cycle (the same ioctl sets all 3 values at once, so there's no reason to require the user to run the program twice to get all 3 things set).
2019-06-18 01:15:00 +00:00
.It Fl E
Enable the PWM channel.
.It Fl p Ar period
Configure the period (in nanoseconds) of the PWM channel.
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
.El
.Sh EXAMPLES
.Bl -bullet
.It
Explain the relationship between PWM hardware channels being controlled and pwmc(4) device filenames. Also, use uppercase PWM when the term is being used as an acronym, and expand the acronym where it's first used.
2019-06-18 00:17:10 +00:00
Show the configuration of the PWM channel:
pwm.8: fix markup in synopsis, add -f description Reviewed by: bcr, manu Differential revision: https://reviews.freebsd.org/D18829
2019-02-06 04:00:37 +00:00
.Bd -literal
Follow changes in the pwmc(4) driver in relation to device filenames. The driver now names its cdev nodes pwmcX.Y where X is unit number and Y is the channel within that unit. Change the default device name from pwmc0 to pwmc0.0. The driver now puts cdev files and label aliases in the /dev/pwm directory, so allow the user to provide unqualified names with -f and automatically prepend the /dev/pwm part for them. Update the examples in the manpage to show the new device name format and location within /dev/pwm.
2019-06-17 16:43:33 +00:00
pwm -f /dev/pwm/pwmc0.1 -C
pwm.8: fix markup in synopsis, add -f description Reviewed by: bcr, manu Differential revision: https://reviews.freebsd.org/D18829
2019-02-06 04:00:37 +00:00
.Ed
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
.It
Rearrange the argument checking and processing so that enable and disable can be combined with configuring the period and duty cycle (the same ioctl sets all 3 values at once, so there's no reason to require the user to run the program twice to get all 3 things set).
2019-06-18 01:15:00 +00:00
Configure a 50000 ns period and a 25000 ns duty cycle
and enable the channel:
pwm.8: fix markup in synopsis, add -f description Reviewed by: bcr, manu Differential revision: https://reviews.freebsd.org/D18829
2019-02-06 04:00:37 +00:00
.Bd -literal
Rearrange the argument checking and processing so that enable and disable can be combined with configuring the period and duty cycle (the same ioctl sets all 3 values at once, so there's no reason to require the user to run the program twice to get all 3 things set).
2019-06-18 01:15:00 +00:00
pwm -f pwmc1.1 -E -p 50000 -d 25000
pwm.8: fix markup in synopsis, add -f description Reviewed by: bcr, manu Differential revision: https://reviews.freebsd.org/D18829
2019-02-06 04:00:37 +00:00
.Ed
pwm(8): Add percentage value support for duty cycle
2018-12-14 18:38:10 +00:00
.It
Follow changes in the pwmc(4) driver in relation to device filenames. The driver now names its cdev nodes pwmcX.Y where X is unit number and Y is the channel within that unit. Change the default device name from pwmc0 to pwmc0.0. The driver now puts cdev files and label aliases in the /dev/pwm directory, so allow the user to provide unqualified names with -f and automatically prepend the /dev/pwm part for them. Update the examples in the manpage to show the new device name format and location within /dev/pwm.
2019-06-17 16:43:33 +00:00
Configure a 50% duty cycle on the device and channel which
were configured in
.Xr pwmc 4
to have the label
.Pa backlight :
pwm.8: fix markup in synopsis, add -f description Reviewed by: bcr, manu Differential revision: https://reviews.freebsd.org/D18829
2019-02-06 04:00:37 +00:00
.Bd -literal
Follow changes in the pwmc(4) driver in relation to device filenames. The driver now names its cdev nodes pwmcX.Y where X is unit number and Y is the channel within that unit. Change the default device name from pwmc0 to pwmc0.0. The driver now puts cdev files and label aliases in the /dev/pwm directory, so allow the user to provide unqualified names with -f and automatically prepend the /dev/pwm part for them. Update the examples in the manpage to show the new device name format and location within /dev/pwm.
2019-06-17 16:43:33 +00:00
pwm -f backlight -d 50%
pwm.8: fix markup in synopsis, add -f description Reviewed by: bcr, manu Differential revision: https://reviews.freebsd.org/D18829
2019-02-06 04:00:37 +00:00
.Ed
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
.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 .
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