From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Subject: Re: [PATCH v2 5/5] OMAPDSS: HDMI: Add support to dump clocks through Date: Fri, 23 Sep 2011 09:01:08 +0300 Message-ID: <1316757668.1901.12.camel@deskari> References: <1316678866-17749-1-git-send-email-mythripk@ti.com> <1316678866-17749-2-git-send-email-mythripk@ti.com> <1316678866-17749-3-git-send-email-mythripk@ti.com> <1316678866-17749-4-git-send-email-mythripk@ti.com> <1316678866-17749-5-git-send-email-mythripk@ti.com> <1316678866-17749-6-git-send-email-mythripk@ti.com> <1316692870.2442.24.camel@deskari> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from na3sys009aog109.obsmtp.com ([74.125.149.201]:43334 "EHLO na3sys009aog109.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751325Ab1IWGBN (ORCPT ); Fri, 23 Sep 2011 02:01:13 -0400 Received: by mail-bw0-f54.google.com with SMTP id zs8so4038704bkb.41 for ; Thu, 22 Sep 2011 23:01:12 -0700 (PDT) In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "K, Mythri P" Cc: linux-omap@vger.kernel.org On Fri, 2011-09-23 at 11:22 +0530, K, Mythri P wrote: > > - What is dcofreq? Looking at the code, it tells if the pixel clock is > > > 1000MHz. Why is such a field needed, can't the HDMI driver manage that > > itself? And if it's needed, why is it called dcofreq, the name doesn't > > make much sense to me. > It is DCO frequency, It suggest the frequency selector range , The field is not DCO frequency, it's a boolean, 0 or 1. That's why the name doesn't really make sense to me. > HDMI_PLL_CONFIGURATION2 (3:1) has to be set accordingly by the driver > depending on whether the CLKOUTLDO is greater than or less than > 1000Mhz, but anyways the decision is taken by the driver. But can't it be done in the ti_hdmi driver, at the same time when programming the registers? Why do we need to set the boolean beforehand. > Also the name is as suggested by TRM . I couldn't find boolean dcofreq in the TRM. > > - We are doing HDMI PLL calculations in the omapdss drivers hdmi.c file. > > The PLL calculations are PLL specific, and thus should be in the > > specific HDMI implementation file, right? > > > >> + seq_printf(s, "DISPC clock source %s (%s)\t(%s)\n", > >> + dss_get_generic_clk_source_name(dispc_clk_src), > >> + dss_feat_get_clk_source_name(dispc_clk_src), > >> + dispc_clk_src == OMAP_DSS_CLK_SRC_FCK ? > >> + "off" : "on"); > > > > Why do you print DISPC clock source? How is that part of HDMI clock > > configuration? > Reason is to check whether the DISPC clock source is PRCM / DSI PLL, > Because DSI PLL might not be sufficient. But it's already printed by the DISPC section, and it's not part of HDMI, so I don't quite see the need. What do you mean DSI PLL might not be sufficient? We can get higher DISPC clocks with DSI PLL than with PRCM. Tomi