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=-14.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 16965C43461 for ; Thu, 10 Sep 2020 08:26:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CAB9520872 for ; Thu, 10 Sep 2020 08:26:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730418AbgIJI0f (ORCPT ); Thu, 10 Sep 2020 04:26:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728709AbgIJIRJ (ORCPT ); Thu, 10 Sep 2020 04:17:09 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8EF2C061756; Thu, 10 Sep 2020 01:16:59 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id 3E3EF29B5AA Subject: Re: [PATCH 1/2] arm64: dts: mt8173: elm: Set uart0 to mmio32 iotype To: Hsin-Yi Wang Cc: "moderated list:ARM/Mediatek SoC support" , Rob Herring , Matthias Brugger , Devicetree List , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , lkml References: <20200910054635.3337487-1-hsinyi@chromium.org> From: Enric Balletbo i Serra Message-ID: <944325c1-818e-934c-907d-7ff0493446b4@collabora.com> Date: Thu, 10 Sep 2020 10:16:55 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Hsin-Yi, On 10/9/20 9:57, Hsin-Yi Wang wrote: > On Thu, Sep 10, 2020 at 3:20 PM Enric Balletbo i Serra > wrote: >> >> Hi Hsin-Yi, >> >> On 10/9/20 7:46, Hsin-Yi Wang wrote: >>> Set uart0 iotype to mmio32 to make earlycon work with stdout-path. >>> >>> Signed-off-by: Hsin-Yi Wang >>> --- >>> arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi >>> index a5a12b2599a4a..d54e62f72c65d 100644 >>> --- a/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi >>> +++ b/arch/arm64/boot/dts/mediatek/mt8173-elm.dtsi >>> @@ -1160,6 +1160,8 @@ &thermal { >>> }; >>> >>> &uart0 { >>> + reg-io-width = <4>; >>> + reg-shift = <2>; >> >> I am wondering if these properties are common enough to go to mt8173.dtsi >> instead of here. >> > Since stdout-path is set on elm.dtsi (using uart0), so I add this > attribute here. > Why needs to be defined in the same place that stdout-path is set? My guess is that reg-io-width and reg-shift are SoC specific, as they define how the IO access to the register is done. In fact, I think that these properties should be added in all the uarts, not only the one that has defined the stdout-path. Cheers, Enric