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.\" $FreeBSD$ 27.\" 28.Dd February 22, 2010 29.Dt SMU 4 30.Os 31.Sh NAME 32.Nm smu 33.Nd Apple System Management Unit Driver 34.Sh SYNOPSIS 35To compile this driver into the kernel, 36place the following lines in your 37kernel configuration file: 38.Bd -ragged -offset indent 39.Cd "device smu" 40.Ed 41.Sh DESCRIPTION 42The 43.Nm 44driver provides support for the System Management Unit (SMU) found in many 45Apple G5 systems. 46This includes most Power Macintosh G5 and all iMac G5 systems. 47.Pp 48The Apple SMU controller provides software power management and thermal 49control functionality, and is responsible for managing system cooling 50devices. 51.Sh HARDWARE 52Chips supported by the 53.Nm 54driver include: 55.Pp 56.Bl -bullet -compact 57.It 58Apple System Management Unit 59.El 60.Sh THERMAL MANAGEMENT 61The 62.Nm 63driver provides basic automatic thermal management. Without a userspace 64daemon providing more advanced control, the driver will attempt to maintain 65system temperatures in a conservative range through coarse-grained control of 66system cooling devices (see below). Automatic kernel-level thermal control 67will take over if more than 3 seconds elapses between userspace cooling 68setting adjustments. 69.Sh SYSCTL VARIABLES 70The 71.Nm 72driver provides power management services and thermal readout through a 73sysctl interface. 74The following sysctls can be used to control the 75power management behavior and to examine current system power and 76thermal conditions. 77.Bl -tag -width indent 78.It Va dev.smu.%d.server_mode 79Restart after power failure behavior (1 causes system to reboot after power 80cut, 0 causes system to remain off). 81.It Va dev.smu.%d.target_temp 82Target system temperature, in degrees Celsius. The 83.Nm 84driver will attempt to adjust fans to maintain the temperature of the 85warmest component in the system at or below this level. 86.It Va dev.smu.%d.critical_temp 87System critical temperature, in degrees Celsius. If any component in 88the system exceeds this temperature, the machine will be shut down within 89500 ms. 90.It Va dev.smu.%d.fans.%s.minrpm 91Minimum allowed speed for this fan. 92.It Va dev.smu.%d.fans.%s.maxrpm 93Maximum allowed speed for this fan. 94.It Va dev.smu.%d.fans.%s.rpm 95Current speed for this fan. The fan speed can be adjusted by changing this 96sysctl. If more than 3 seconds elapses between fan speed adjustments, the 97kernel will resume automatic control of the fan. 98.It Va dev.smu.%d.sensors.%s 99Current reading from this sensor. Four sensor types are supported. Temperature 100sensors are in units of degrees Celsius, current sensors in milliamps, voltage 101sensors 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 pmu 4 , 113.Xr led 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 125.Aq nwhitehorn@FreeBSD.org . 126