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Fix a few typos and Xrefs, use Dq, comment out Xr to non-existent gpioattach(4), 

sort SEE ALSO.
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wiz 2011-11-13 19:31:05 +00:00
parent 3aa8e3d303
commit 7405dbf494
1 changed files with 28 additions and 15 deletions
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43
share/man/man4/gpiopwm.4
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@ -1,4 +1,4 @@
.\" $NetBSD: gpiopwm.4,v 1.1 2011/11/13 12:35:40 mbalmer Exp $
.\" $NetBSD: gpiopwm.4,v 1.2 2011/11/13 19:31:05 wiz Exp $
.\"
.\" Copyright (c) 2011 Marc Balmer <marc@msys.ch>
.\"
@ -14,7 +14,7 @@
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd Novemner 13, 2011
.Dd November 13, 2011
.Dt GPIOPWM 4
.Os
.Sh NAME
@ -29,29 +29,42 @@ The
driver allows for pulsing GPIO pins in software using the
.Xr callout 9
facility.
The pulse frequency and duty cycle are specified indirectly by setting an 'on'
and 'off' period, in ticks.
The pulse frequency and duty cycle are specified indirectly by setting an
.Dq on
and
.Dq off
period, in ticks.
Both values are accessible as
.Xr sysctl 2
.Xr sysctl 3
variables.
.Sh SYSCTL VARIABLES
The following
.Xr sysctl 2
.Xr sysctl 3
variables are used to define the pulsing:
.Bl -tag width
.It hw.gpiopwmN.off
Define the 'off' period in ticks.
Define the
.Dq off
period in ticks.
.It hw.gpiopwmN.on
Define the 'on' period in ticks.
Define the
.Dq on
period in ticks.
.El
.Pp
Only when both the 'on' and the 'off' period are set to values higher than
zero pulsing will start.
Only when both the
.Dq on
and the
.Dq off
period are set to values higher than zero pulsing will start.
To stop the pulsing, set either value to zero.
.Sh EXAMPLES
To pulse a pin on a machine with 100 ticks/second with a frequency of 1Hz and a
duty cycle of 20%, the 'on' period must be set to 20 and the 'off' perdiod
must be set to 80.
duty cycle of 20%, the
.Dq on
period must be set to 20 and the
.Dq off
period must be set to 80.
The following example will pulse the error LED of a Soekris net4801
with a frequency of 1 Hz and a duty cycle of 20%:
.Bd -literal
@ -62,10 +75,10 @@ with a frequency of 1 Hz and a duty cycle of 20%:
.Ed
.Sh SEE ALSO
.Xr gpio 4 ,
.Xr gpioattach 4 ,
.\" .Xr gpioattach 4 ,
.Xr intro 4 ,
.Xr gpioctl 8 ,
.Xr sysctl 8 ,
.Xr intro 4
.Xr sysctl 8
.Sh HISTORY
The
.Nm