82 lines
2.8 KiB
Groff
82 lines
2.8 KiB
Groff
.\" $NetBSD: mcp980x.4,v 1.5 2013/10/15 14:51:58 rkujawa Exp $
|
|
.\"
|
|
.\" Copyright (c) 2013 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Radoslaw Kujawa.
|
|
.\"
|
|
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 October 15, 2013
|
|
.Dt MCP980X 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm mcp980x
|
|
.Nd Microchip 9800/1/2/3 I2C temperature sensor driver
|
|
.Sh SYNOPSIS
|
|
.Cd "mcp980x* at iic? addr 0x48"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
driver provides support for the MCP980x series of temperature sensors.
|
|
It allows reporting ambient temperature through the
|
|
.Xr envsys 4
|
|
API.
|
|
.Sh SYSCTL VARIABLES
|
|
The following
|
|
.Xr sysctl 3
|
|
variable are provided:
|
|
.Bl -tag -width machdep.mcp980x0.hysteresis
|
|
.It Va machdep.mcp980x0.res
|
|
ADC resolution (integer).
|
|
Valid values are 0-3, where 0 is 9-bit (0.5 Celsius degree) and 3 is 12-bit
|
|
(0.0625 Celsius degree) resolution.
|
|
.It Va machdep.mcp980x0.templimit
|
|
If the ambient temperature exceeds this limit, the chip asserts an alert line
|
|
(integer).
|
|
.It Va machdep.mcp980x0.hysteresis
|
|
Hysteresis for temperature limit (integer).
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr envsys 4
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
device first appeared in
|
|
.Nx 7.0 .
|
|
.Sh AUTHORS
|
|
.An -nosplit
|
|
The
|
|
.Nm
|
|
driver was written by
|
|
.An Radoslaw Kujawa Aq Mt radoslaw.kujawa@gmail.com .
|
|
.Sh CAVEATS
|
|
MCP9805 chip is different and is supported by the
|
|
.Xr sdtemp 4
|
|
driver.
|
|
.Pp
|
|
The MCP980x chip supports hysteresis and temperature limit values with a
|
|
resolution of 0.5 Celsius degree, however the
|
|
.Nm
|
|
driver supports setting only integer values.
|