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freebsd-skq/share/man/man4/owc.4

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New 1-Wire bus implementation. 1-Wire controller is abstracted, though only gpiobus configured via FDT is supported. Bus enumeration is supported. Devices are created for each device found. 1-Wire temperature controllers are supported, but other drivers could be written. Temperatures are polled and reported via a sysctl. Errors are reported via sysctl counters. Mis-wired bus detection is included for more trouble shooting. See ow(4), owc(4) and ow_temp(4) for details of what's supported and known issues. This has been tested on Raspberry Pi-B, Pi2 and Beagle Bone Black with up to 7 devices. Differential Revision: https://reviews.freebsd.org/D2956 Relnotes: yes MFC after: 2 weeks Reviewed by: loos@ (with many insightful comments)
2015-08-27 23:33:38 +00:00
.\"
Regularize my copyright notice o Remove All Rights Reserved from my notices o imp@FreeBSD.org everywhere o regularize punctiation, eliminate date ranges o Make sure that it's clear that I don't claim All Rights reserved by listing All Rights Reserved on same line as other copyright holders (but not me). Other such holders are also listed last where it's clear.
2019-12-04 16:56:11 +00:00
.\" Copyright (c) 2015 M. Warner Losh <imp@FreeBSD.org>
New 1-Wire bus implementation. 1-Wire controller is abstracted, though only gpiobus configured via FDT is supported. Bus enumeration is supported. Devices are created for each device found. 1-Wire temperature controllers are supported, but other drivers could be written. Temperatures are polled and reported via a sysctl. Errors are reported via sysctl counters. Mis-wired bus detection is included for more trouble shooting. See ow(4), owc(4) and ow_temp(4) for details of what's supported and known issues. This has been tested on Raspberry Pi-B, Pi2 and Beagle Bone Black with up to 7 devices. Differential Revision: https://reviews.freebsd.org/D2956 Relnotes: yes MFC after: 2 weeks Reviewed by: loos@ (with many insightful comments)
2015-08-27 23:33:38 +00:00
.\"
.\" 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. The name of the author may not be used to endorse or promote products
.\" derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" 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
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.\"
.\" $FreeBSD$
.\"
owc.4: document how to set up the 1-wire bus on a device.hints system MFC after: 1 week
2019-06-26 06:40:30 +00:00
.Dd June 26, 2019
New 1-Wire bus implementation. 1-Wire controller is abstracted, though only gpiobus configured via FDT is supported. Bus enumeration is supported. Devices are created for each device found. 1-Wire temperature controllers are supported, but other drivers could be written. Temperatures are polled and reported via a sysctl. Errors are reported via sysctl counters. Mis-wired bus detection is included for more trouble shooting. See ow(4), owc(4) and ow_temp(4) for details of what's supported and known issues. This has been tested on Raspberry Pi-B, Pi2 and Beagle Bone Black with up to 7 devices. Differential Revision: https://reviews.freebsd.org/D2956 Relnotes: yes MFC after: 2 weeks Reviewed by: loos@ (with many insightful comments)
2015-08-27 23:33:38 +00:00
.Dt OWC 4
.Os
.Sh NAME
.Nm owc
.Nd Dallas Semiconductor 1-Wire Controller
.Sh SYNOPSIS
.Cd device owc
.Sh DESCRIPTION
The
.Nm
module implements Dallas Semiconductor 1-Wire signaling.
It attaches the
.Xr ow 4
driver 1-Wire bus protocol.
The
.Nm
device implements the Link Layer of the 1-Wire bus protocol stack.
.Pp
Bit banging a pin on a
.Xr gpiobus 4
is the only supported controller.
Both standard and overdrive transfer timings are implemented.
Strong pull-up functionality needed to support parasitic mode is not
implemented.
.Pp
To enable 1-Wire for FDT systems requires modifying the DTS for your
board to add something like:
.Bd -literal
/ {
...
onewire {
compatible = "w1-gpio";
gpios = <&gpio 4 1>;
};
...
};
.Ed
.Pp
The gpios property describes the GPIO pin the 1-Wire bus is connected
to.
For more details about the
.Va gpios
property, please consult
Move sys/boot/fdt/dts to sys/dts and adjust scripts. Sponsored by: Netflix
2017-11-14 21:03:57 +00:00
.Pa /usr/src/sys/dts/bindings-gpio.txt .
owc.4: document how to set up the 1-wire bus on a device.hints system MFC after: 1 week
2019-06-26 06:40:30 +00:00
.Pp
On a
.Xr device.hints 5
based system these values are required for the
.Nm :
.Bl -tag -width ".Va hint.owc.%d.atXXX"
.It Va hint.owc.%d.at
The
.Nm gpiobus
you are attaching to.
.It Va hint.owc.%d.pins
This is a bitmask that defines a pin on the
.Nm gpiobus
that is to be used for the 1-Wire bus.
For instance, to configure pin 10, use the bitmask of 0x400.
Please note that this mask should have only one bit set
(any other bits - i.e., pins - will be ignored).
fix up r349406, add missing .El MFC after: 1 week
2019-06-26 07:08:51 +00:00
.El
New 1-Wire bus implementation. 1-Wire controller is abstracted, though only gpiobus configured via FDT is supported. Bus enumeration is supported. Devices are created for each device found. 1-Wire temperature controllers are supported, but other drivers could be written. Temperatures are polled and reported via a sysctl. Errors are reported via sysctl counters. Mis-wired bus detection is included for more trouble shooting. See ow(4), owc(4) and ow_temp(4) for details of what's supported and known issues. This has been tested on Raspberry Pi-B, Pi2 and Beagle Bone Black with up to 7 devices. Differential Revision: https://reviews.freebsd.org/D2956 Relnotes: yes MFC after: 2 weeks Reviewed by: loos@ (with many insightful comments)
2015-08-27 23:33:38 +00:00
.Sh SEE ALSO
.Xr gpiobus 4 ,
.Xr ow 4 ,
.Xr ow_temp 4 ,
.Xr owll 9 ,
.Xr own 9
.Sh LEGAL
.Tn 1-Wire
is a registered trademark of Maxim Integrated Products, Inc.
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 11.0 .
.Sh AUTHORS
The
.Nm
device driver and this manual page were written by
.An Warner Losh .
.Sh CAVEATS
The gpio driver implements timing by busy waiting, which can cause a
high load on slower systems.
.Sh BUGS
Overdrive mode has not actually been tested.
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