.\" Copyright (c) 2020 Vladimir Kondratyev <wulf@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 AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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.
.\"
.Dd September 21, 2020
.Dt IICHID 4
.Os
.Sh NAME
.Nm iichid
.Nd I2C HID transport driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device iichid"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
iichid_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides a interface to I2C Human Interface Devices (HIDs).
.Sh SYSCTL VARIABLES
Next parameters are available as
.Xr sysctl 8
variables.
Debug parameter is available as
.Xr loader 8
tunable as well.
.Bl -tag -width indent
.It Va dev.iichid.*.sampling_rate_fast
Active sampling rate in num/second (for sampling mode).
.It Va dev.iichid.*.sampling_rate_slow
Idle sampling rate in num/second (for sampling mode).
.It Va dev.iichid.*.sampling_hysteresis
Number of missing samples before enabling of slow mode (for sampling mode).
.It Va hw.iichid.debug
Debug output level, where 0 is debugging disabled and larger values increase
debug message verbosity.
Default is 0.
.El
.Sh SEE ALSO
.Xr ig4 4
.Sh BUGS
The
.Nm
does not support GPIO interrupts yet.
In that case
.Nm
enables sampling mode with periodic polling of hardware by driver means.
See dev.iichid.*.sampling_*
.Xr sysctl 8
variables for tuning of sampling parameters.
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 13.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Marc Priggemeyer Aq Mt marc.priggemeyer@gmail.com
and
.An Vladimir Kondratyev Aq Mt wulf@FreeBSD.org .
.Pp
This manual page was written by
.An Vladimir Kondratyev Aq Mt wulf@FreeBSD.org .