From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gary Thomas Subject: DSS2 clocking Date: Wed, 21 Oct 2009 06:42:41 -0600 Message-ID: <4ADF01C1.3020602@mlbassoc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from hermes.mlbassoc.com ([76.76.67.137]:56490 "EHLO mail.chez-thomas.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752734AbZJUMmh (ORCPT ); Wed, 21 Oct 2009 08:42:37 -0400 Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tomi Valkeinen Cc: OMAP Linux discussion I'm using DSS2, currently just with a frame buffer to a [VGA/RGB] monitor. I'm trying to understand how to set the timing parameters for my device. The simple 'omapfb.mode=1024x768-24@75' doesn't quite cut it for some of the devices I need to use. Questions: * How can I get different pixel clocks? I seem to always end up with 61714285: # cat /tmp/dbg/omapdss/clk - dss - internal clk count 2 dss_ick 83000000 1 dss1_alwon_fck 123428570 1 dss2_alwon_fck 13000000 0 dss_tv_fck 54000000 0 dss_96m_fck 96000000 0 - dispc - dispc fclk source = dss1_alwon_fclk pixel clk = 123428570 / 1 / 2 = 61714285 * How can I control the waveform? In particular, the size and shape of the "porches"? My display seems to need these settings: 61714,1024/26/162/136,768/3/29/6 I'd like to get this behaviour, either from the boot line or ideally by default. * The display also seems to want the sync pulses to be asserted low (inverted?). Currently, I have this "hard-wired" into my display device, but I'd also like this to be adjustable. Thanks for any pointers, etc. Note: I'm using Tomi's tree from roughly late July http://www.bat.org/~tomba/git/linux-omap-dss.git 7ae220f46384b34e72b8c3b0c2075a674a3f74fe Thanks for any pointers -- ------------------------------------------------------------ Gary Thomas | Consulting for the MLB Associates | Embedded world ------------------------------------------------------------