From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.185]) by ozlabs.org (Postfix) with ESMTP id 5E0FF67DD5 for ; Wed, 8 Nov 2006 16:01:22 +1100 (EST) Received: by nf-out-0910.google.com with SMTP id n15so322975nfc for ; Tue, 07 Nov 2006 21:01:19 -0800 (PST) Message-ID: <348caa310611072101w3db2bd1cta97c52b63b2a29fc@mail.gmail.com> Date: Wed, 8 Nov 2006 10:31:19 +0530 From: "Prakash Ramaraju" Sender: prakash.org@gmail.com To: linuxppc-embedded@ozlabs.org Subject: Clock Modification of MPC885 for USB Host Functionality MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Greetings Currently I have a MPC885 based board running at 50MHz. I want USB host working at full speed with internal clock. Assuming I need to change the General System Clock Frequency (GCLK2) to 48MHz, I got this calculation with input frequency of 10MHz from an u-boot script. pdf mfi mfn mfd s dbrmo dpref dpgdck jdbck gclk2 exact? --- --- --- --- - ----- ----- ------ ----- ----- ------ 0 9 3 4 1 0 10000000 192000000 96000000 48000000 YES 0 9 6 9 1 0 10000000 192000000 96000000 48000000 YES 0 9 9 14 1 0 10000000 192000000 96000000 48000000 YES 0 9 12 19 1 0 10000000 192000000 96000000 48000000 YES I modified CFG_PLPRCR (to 19194000) in u-boot config file to match this. But I'm getting only 45MHz output clock (not exactly 48MHz which is needed for USB to work) If anyone can shed some info making the USB work on MPC885 with internal clock or changing the clock freq to exact 48MHz, it will be helpful. -- With best regards, Prakash