From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C380DC433EF for ; Thu, 9 Jun 2022 15:00:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245186AbiFIPAA (ORCPT ); Thu, 9 Jun 2022 11:00:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241569AbiFIO7w (ORCPT ); Thu, 9 Jun 2022 10:59:52 -0400 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CFC8A1F8993; Thu, 9 Jun 2022 07:59:50 -0700 (PDT) Received: (Authenticated sender: peter@korsgaard.com) by mail.gandi.net (Postfix) with ESMTPSA id C09A3C000D; Thu, 9 Jun 2022 14:59:46 +0000 (UTC) Received: from peko by dell.be.48ers.dk with local (Exim 4.94.2) (envelope-from ) id 1nzJdR-0029HW-SW; Thu, 09 Jun 2022 16:59:45 +0200 From: Peter Korsgaard To: Alexandre Belloni Cc: Srinivas Neeli , a.zummo@towertech.it, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, michal.simek@xilinx.com, sgoud@xilinx.com, shubhraj@xilinx.com, srinivas.neeli@amd.com, neelisrinivas18@gmail.com, devicetree@vger.kernel.org, linux-rtc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, git@xilinx.com Subject: Re: [PATCH V6 2/2] rtc: zynqmp: Add calibration set and get support References: <20220609140833.1784738-1-srinivas.neeli@xilinx.com> <20220609140833.1784738-2-srinivas.neeli@xilinx.com> <87r13x28o4.fsf@dell.be.48ers.dk> Date: Thu, 09 Jun 2022 16:59:45 +0200 In-Reply-To: (Alexandre Belloni's message of "Thu, 9 Jun 2022 16:53:46 +0200") Message-ID: <87mtel287y.fsf@dell.be.48ers.dk> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "Alexandre" == Alexandre Belloni writes: > On 09/06/2022 16:50:03+0200, Peter Korsgaard wrote: >> >>>>> "Srinivas" == Srinivas Neeli writes: >> >> > Zynqmp RTC controller has a calibration feature to compensate >> > time deviation due to input clock inaccuracy. >> > Set and get calibration API's are used for setting and getting >> > calibration value from the controller calibration register. >> > As per RTC spec default calibration value is 0x7FFF. >> >> Where do you see that? ug1085 rev2.2 still lists: >> >> Programming Sequences >> init rtc >> 1. Write the value 0019_8231h into the calibration register, CALIB_WRITE. >> > This is a very weird value. Last time I had a look, I couldn't find an > explanation for it. Agreed. I am not arguing that it is sensible, I just wondered where this new value comes from? -- Bye, Peter Korsgaard