1.\" 2.\" Copyright (c) 2007 3.\" The DragonFly Project. 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.\" 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in 13.\" the documentation and/or other materials provided with the 14.\" distribution. 15.\" 3. Neither the name of The DragonFly Project nor the names of its 16.\" contributors may be used to endorse or promote products derived 17.\" from this software without specific, prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 22.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 23.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 24.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 25.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 27.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 28.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 29.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.Dd October 10, 2014 33.Dt POWERNOW 4 34.Os 35.Sh NAME 36.Nm powernow 37.Nd PowerNow! Technology support 38.Sh SYNOPSIS 39To compile this driver into the kernel, place the following line in your 40kernel configuration file: 41.Bd -ragged -offset indent 42.Cd "options CPU_ENABLE_POWERNOW" 43.Ed 44.Pp 45To load this driver as a module at boot time, place the following line in 46.Xr loader.conf 5 : 47.Bd -literal -offset indent 48powernow_load="YES" 49.Ed 50.Sh DESCRIPTION 51The 52.Nm 53driver provides support for the 54.Tn PowerNow! Technology 55present in AMD K8 CPUs. 56Please note that 57.Xr powerd 8 58should be preferred if it is working properly on your system. 59.Pp 60If the CPU is supported 61.Nm 62creates the following variables in the 63.Va machdep.powernow 64branch of the 65.Xr sysctl 3 66MIB. 67.Bl -tag -width ".Va frequency.available" -offset indent 68.It Va frequency.available 69The list of frequencies supported by 70.Nm 71for the CPU (read only). 72.It Va frequency.current 73The current CPU frequency (read only). 74.It Va frequency.target 75The target CPU frequency (read/write). 76.El 77.Sh SEE ALSO 78.Xr powerd 8 79.Sh HISTORY 80The 81.Nm 82driver first appeared in 83.Dx 2.3 . 84