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.\" Copyright (c) 2015 M. Warner Losh
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.\" $FreeBSD: head/share/man/man9/owll.9 287225 2015-08-27 23:33:38Z imp $
.\"
.Dd July 20, 2015
.Dt OWLL 9
.Os
.Sh NAME
.Nm owll
.Nm OWLL_WRITE_ONE,
.Nm OWLL_WRITE_ZERO,
.Nm OWLL_READ_DATA,
.Nm OWLL_REASET_AND_PRESENCE
.Nd Dallas Semiconductor 1-Wire Link Layer Interface
.Sh SYNOPSIS
.Ft int
.Fn OWLL_WRITE_ONE "device_t lldev" "struct ow_timing *timing"
.Ft int
.Fn OWLL_WRITE_ZERO "device_t lldev" "struct ow_timing *timing"
.Ft int
.Fn OWLL_READ_DATA "device_t lldev" "struct ow_timing *timing" "int *bit"
.Ft int
.Fn OWLL_RESET_AND_PRESENCE "device_t lldev" "struct ow_timing *timing" "int *bit"
.Sh DESCRIPTION
The
.Nm
interface provides access to the link layer of the Dallas
Semiconductor 1-Wire from upper layers of the protocol.
.Pp
.Fn OWLL_WRITE_ONE
and
.Fn OWLL_WRITE_ZERO
writes a one bitor a zero bit respectively on the 1-Wire bus.
.Pp
.Fn OWLL_READ_DATA
reads one bit from the 1-Wire bus.
This is often referred to as a
.Dq Read Time Slot
in the 1-Wire device data sheets.
.Pp
The
.Fn OWLL_RESET_AND_PRESENCE
function starts a reset sequence and detects if any device(s) are
present on the bus.
This is the beginning of all 1-Wire transactions.
.Sh NOTES
This interface is intended to be used only by the
.Xr ow 4
device to talk to the low-level bus.
By convention, the device that implements this interface is called
.Xr owc 4 .
Only devices that implement
.Xr own 9
should call these interfaces.
.Sh SEE ALSO
.Xr ow 4 ,
.Xr owc 4 ,
.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 .