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 March 17, 2011 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. 56.Pp 57If the CPU is supported 58.Nm 59creates the following variables in the 60.Va machdep.powernow 61branch of the 62.Xr sysctl 3 63MIB. 64.Bl -tag -width ".Va frequency.available" -offset indent 65.It Va frequency.available 66The list of frequencies supported by 67.Nm 68for the CPU (read only). 69.It Va frequency.current 70The current CPU frequency (read only). 71.It Va frequency.target 72The target CPU frequency (read/write). 73.El 74.Sh HISTORY 75The 76.Nm 77driver first appeared in 78.Dx 2.3 . 79