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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3265AC32751 for ; Wed, 7 Aug 2019 10:55:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1334121E6C for ; Wed, 7 Aug 2019 10:55:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729211AbfHGKzG (ORCPT ); Wed, 7 Aug 2019 06:55:06 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:35495 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726734AbfHGKzG (ORCPT ); Wed, 7 Aug 2019 06:55:06 -0400 X-Originating-IP: 90.65.161.137 Received: from localhost (lfbn-1-1545-137.w90-65.abo.wanadoo.fr [90.65.161.137]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 7C5B320003; Wed, 7 Aug 2019 10:55:03 +0000 (UTC) Date: Wed, 7 Aug 2019 12:55:02 +0200 From: Alexandre Belloni To: Chen-Yu Tsai , Mark Rutland , Alessandro Zummo , devicetree , Maxime Ripard , linux-kernel , linux-sunxi , Rob Herring , linux-arm-kernel , linux-rtc@vger.kernel.org Subject: Re: [linux-sunxi] [PATCH 0/3] Add basic support for RTC on Allwinner H6 SoC Message-ID: <20190807105502.GK3600@piout.net> References: <20190412120730.473-1-megous@megous.com> <20190806183045.edhm3qzpegscf2z7@core.my.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190806183045.edhm3qzpegscf2z7@core.my.home> User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 06/08/2019 20:30:45+0200, Ondřej Jirman wrote: > Maybe whether XO or DCXO is used also matters if you want to do some fine > tunning of DCXO (control register has pletny of options), but that's probably > better done in u-boot. And there's still no need to read HOSC source from DT. > The driver can just check compatible, and if it is H6 and OSC_CLK_SRC_SEL is 1, > it can do it's DCXO tunning, or whatever. But neither OS nor bootloader will > be using this info to gate/disable the osciallator. > It is actually useful to be able to tweak the crystal tuning at runtime to be able to reduce clock drift and compare with a reliable source (e.g. NTP). I'm curious, what kind of options does this RTC have? -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com