1.\" 2.\" Copyright (c) 2015 M. Warner Losh <imp@FreeBSD.org> 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. The name of the author may not be used to endorse or promote products 10.\" derived from this software without specific prior written permission. 11.\" 12.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 13.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 14.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 15.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 16.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 17.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 18.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 19.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 20.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 21.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 22.\" SUCH DAMAGE. 23.\" 24.Dd September 22, 2016 25.Dt OWLL 9 26.Os 27.Sh NAME 28.Nm owll , 29.Nm OWLL_WRITE_ONE , 30.Nm OWLL_WRITE_ZERO , 31.Nm OWLL_READ_DATA , 32.Nm OWLL_REASET_AND_PRESENCE 33.Nd Dallas Semiconductor 1-Wire Link Layer Interface 34.Sh SYNOPSIS 35.Ft int 36.Fn OWLL_WRITE_ONE "device_t lldev" "struct ow_timing *timing" 37.Ft int 38.Fn OWLL_WRITE_ZERO "device_t lldev" "struct ow_timing *timing" 39.Ft int 40.Fn OWLL_READ_DATA "device_t lldev" "struct ow_timing *timing" "int *bit" 41.Ft int 42.Fn OWLL_RESET_AND_PRESENCE "device_t lldev" "struct ow_timing *timing" "int *bit" 43.Sh DESCRIPTION 44The 45.Nm 46interface provides access to the link layer of the Dallas 47Semiconductor 1-Wire from upper layers of the protocol. 48.Pp 49.Fn OWLL_WRITE_ONE 50and 51.Fn OWLL_WRITE_ZERO 52writes a one bit or a zero bit respectively on the 1-Wire bus. 53.Pp 54.Fn OWLL_READ_DATA 55reads one bit from the 1-Wire bus. 56This is often referred to as a 57.Dq Read Time Slot 58in the 1-Wire device data sheets. 59.Pp 60The 61.Fn OWLL_RESET_AND_PRESENCE 62function starts a reset sequence and detects if any device(s) are 63present on the bus. 64This is the beginning of all 1-Wire transactions. 65.Sh NOTES 66This interface is intended to be used only by the 67.Xr ow 4 68device to talk to the low-level bus. 69By convention, the device that implements this interface is called 70.Xr owc 4 . 71Only devices that implement 72.Xr own 9 73should call these interfaces. 74.Sh SEE ALSO 75.Xr ow 4 , 76.Xr owc 4 , 77.Xr own 9 78.Sh LEGAL 79.Tn 1-Wire 80is a registered trademark of Maxim Integrated Products, Inc. 81.Sh HISTORY 82The 83.Nm 84driver first appeared in 85.Fx 11.0 . 86.Sh AUTHORS 87The 88.Nm 89device driver and this manual page were written by 90.An Warner Losh . 91