1.\"- 2.\" Copyright (c) 2010 Nathan Whitehorn <nwhitehorn@FreeBSD.org> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 16.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 17.\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 18.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 19.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 20.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 22.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 23.\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 24.\" POSSIBILITY OF SUCH DAMAGE. 25.\" 26.Dd February 22, 2010 27.Dt SMU 4 28.Os 29.Sh NAME 30.Nm smu 31.Nd Apple System Management Unit Driver 32.Sh SYNOPSIS 33To compile this driver into the kernel, 34place the following lines in your 35kernel configuration file: 36.Bd -ragged -offset indent 37.Cd "device smu" 38.Ed 39.Sh DESCRIPTION 40The 41.Nm 42driver provides support for the System Management Unit (SMU) found in many 43Apple G5 systems. 44This includes most Power Macintosh G5 and all iMac G5 systems. 45.Pp 46The Apple SMU controller provides software power management and thermal 47control functionality, and is responsible for managing system cooling 48devices. 49.Sh HARDWARE 50Chips supported by the 51.Nm 52driver include: 53.Pp 54.Bl -bullet -compact 55.It 56Apple System Management Unit 57.El 58.Sh THERMAL MANAGEMENT 59The 60.Nm 61driver provides basic automatic thermal management. 62Without a userspace daemon providing more advanced control, the driver will 63attempt to maintain system temperatures in a conservative range through 64coarse-grained control of system cooling devices (see below). 65Automatic kernel-level thermal control will take over if more than 3 66seconds elapses between userspace cooling setting adjustments. 67.Sh SYSCTL VARIABLES 68The 69.Nm 70driver provides power management services and thermal readout through a 71sysctl interface. 72The following sysctls can be used to control the power management behavior 73and to examine current system power and thermal conditions. 74.Bl -tag -width indent 75.It Va dev.smu.%d.server_mode 76Restart after power failure behavior (1 causes system to reboot after power 77cut, 0 causes system to remain off). 78.It Va dev.smu.%d.target_temp 79Target system temperature, in degrees Celsius. 80The 81.Nm 82driver will attempt to adjust fans to maintain the temperature of the 83warmest component in the system at or below this level. 84.It Va dev.smu.%d.critical_temp 85System critical temperature, in degrees Celsius. 86If any component in the system exceeds this temperature, the machine 87will be shut down within 500 ms. 88.It Va dev.smu.%d.fans.%s.minrpm 89Minimum allowed speed for this fan. 90.It Va dev.smu.%d.fans.%s.maxrpm 91Maximum allowed speed for this fan. 92.It Va dev.smu.%d.fans.%s.rpm 93Current speed for this fan. 94The fan speed can be adjusted by changing this sysctl. 95If more than 3 seconds elapses between fan speed adjustments, the kernel will 96resume automatic control of the fan. 97.It Va dev.smu.%d.sensors.%s 98Current reading from this sensor. 99Four sensor types are supported. 100Temperature sensors are in units of degrees Celsius, current sensors in 101milliamps, voltage sensors in millivolts, and power sensors in milliwatts. 102.El 103.Sh LED INTERFACE 104The 105.Nm 106driver provides an 107.Xr led 4 108annunciator interface at 109.Pa /dev/led/sleepled . 110.Sh SEE ALSO 111.Xr acpi 4 , 112.Xr led 4 , 113.Xr pmu 4 114.Sh HISTORY 115The 116.Nm 117device driver appeared in 118.Fx 8.0 . 119.Sh AUTHORS 120.An -nosplit 121The 122.Nm 123driver was written by 124.An Nathan Whitehorn Aq Mt nwhitehorn@FreeBSD.org . 125