From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 30 Mar 2004 22:54:59 +0100 (BST) Received: from 206.173.66.57.ptr.us.xo.net ([IPv6:::ffff:206.173.66.57]:44745 "EHLO tibook.embeddededge.com") by linux-mips.org with ESMTP id ; Tue, 30 Mar 2004 22:54:58 +0100 Received: from embeddededge.com (IDENT:dan@localhost.localdomain [127.0.0.1]) by tibook.embeddededge.com (8.11.1/8.11.1) with ESMTP id i2ULuJf00862; Tue, 30 Mar 2004 16:56:19 -0500 Message-ID: <4069ED03.8060202@embeddededge.com> Date: Tue, 30 Mar 2004 16:56:19 -0500 From: Dan Malek Organization: Embedded Edge, LLC. User-Agent: Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:0.9.9) Gecko/20020411 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Bob Lees CC: linux-mips@linux-mips.org Subject: Re: Frequency (cpu speed) control on AU1100 References: <200403302137.38123.bob@diamond.demon.co.uk> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 4699 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: dan@embeddededge.com Precedence: bulk X-list: linux-mips Bob Lees wrote: > ....I suspect I am > missing something somewhere, but I can't find any references to cpu speed > control for the MIPS processors, specically the au1x range. The Au1xxx has a PLL that multiplies the incoming 12 MHz clock up to the internal frequency. Just be aware there are lots of peripheral clocks and bus clocks derived from this internal frequency. There is code in the kernel power management to allow changing the frequency during operation of Linux, but I don't know how well it works today as I have not tested that for quite some time. Thanks. -- Dan