From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nf-out-0910.google.com (nf-out-0910.google.com [64.233.182.191]) by ozlabs.org (Postfix) with ESMTP id 6A48D67C84 for ; Mon, 6 Nov 2006 21:29:15 +1100 (EST) Received: by nf-out-0910.google.com with SMTP id n29so1374077nfc for ; Mon, 06 Nov 2006 02:29:13 -0800 (PST) Message-ID: <348caa310611060229x2baae881n67cf0d4e085e32c6@mail.gmail.com> Date: Mon, 6 Nov 2006 15:59:12 +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: multipart/alternative; boundary="----=_Part_63336_24929328.1162808952701" List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , ------=_Part_63336_24929328.1162808952701 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline 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. Thanks -- With best regards, Prakash ------=_Part_63336_24929328.1162808952701 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline 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.

Thanks

--
With best regards,
Prakash ------=_Part_63336_24929328.1162808952701--