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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 00C84C46464 for ; Fri, 10 Aug 2018 08:13:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A81EF21529 for ; Fri, 10 Aug 2018 08:13:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A81EF21529 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727445AbeHJKm0 (ORCPT ); Fri, 10 Aug 2018 06:42:26 -0400 Received: from mga07.intel.com ([134.134.136.100]:16472 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726610AbeHJKm0 (ORCPT ); Fri, 10 Aug 2018 06:42:26 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Aug 2018 01:13:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,218,1531810800"; d="scan'208";a="247714793" Received: from songjunw-mobl1.ger.corp.intel.com (HELO [10.226.39.42]) ([10.226.39.42]) by orsmga005.jf.intel.com with ESMTP; 10 Aug 2018 01:13:35 -0700 Subject: Re: [PATCH v2 08/18] serial: intel: Get serial id from dts To: Geert Uytterhoeven Cc: hua.ma@linux.intel.com, yixin.zhu@linux.intel.com, chuanhua.lei@linux.intel.com, qi-ming.wu@intel.com, Linux MIPS Mailing List , linux-clk , "open list:SERIAL DRIVERS" , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Greg KH , Linux Kernel Mailing List , Jiri Slaby References: <20180803030237.3366-1-songjun.wu@linux.intel.com> <20180803030237.3366-9-songjun.wu@linux.intel.com> <734bddbc-a5aa-d50d-0e7b-d8adc4d1afb2@linux.intel.com> From: "Wu, Songjun" Message-ID: Date: Fri, 10 Aug 2018 16:13:34 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/8/2018 4:33 PM, Geert Uytterhoeven wrote: > Hi Songjun, > > On Wed, Aug 8, 2018 at 6:05 AM Wu, Songjun wrote: >> On 8/7/2018 3:33 PM, Geert Uytterhoeven wrote: >>> On Fri, Aug 3, 2018 at 5:04 AM Songjun Wu wrote: >>>> Get serial id from dts. >>>> >>>> "#ifdef CONFIG_LANTIQ" preprocessor is used because LTQ_EARLY_ASC >>>> macro is defined in lantiq_soc.h. >>>> lantiq_soc.h is in arch path for legacy product support. >>>> >>>> arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h >>>> >>>> If "#ifdef preprocessor" is changed to >>>> "if (IS_ENABLED(CONFIG_LANTIQ))", when CONFIG_LANTIQ is not enabled, >>>> code using LTQ_EARLY_ASC is compiled. >>>> Compilation will fail for no LTQ_EARLY_ASC defined. >>>> >>>> Signed-off-by: Songjun Wu >>> Thanks for your patch! >>> >>>> @@ -699,9 +700,19 @@ lqasc_probe(struct platform_device *pdev) >>>> return -ENODEV; >>>> } >>>> >>>> - /* check if this is the console port */ >>>> - if (mmres->start != CPHYSADDR(LTQ_EARLY_ASC)) >>>> - line = 1; >>>> + /* get serial id */ >>>> + line = of_alias_get_id(node, "serial"); >>>> + if (line < 0) { >>>> +#ifdef CONFIG_LANTIQ >>>> + if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC)) >>>> + line = 0; >>>> + else >>>> + line = 1; >>>> +#else >>>> + dev_err(&pdev->dev, "failed to get alias id, errno %d\n", line); >>>> + return line; >>> Please note that not providing a fallback here makes life harder when using >>> DT overlays. >>> See the description of commit 7678f4c20fa7670f ("serial: sh-sci: Add support >>> for dynamic instances") for background info. >> Thanks for your comment. >> The logic in commit 7678f4c20fa7670f is not suitable here. >> We need to know which serial instance is used for console. >> We cannot use dynamic serial instance here. > Why does the driver need to use which serial instance is used for the console? > Hardcoding that is not an option, as the board DTS may specify the console using > chosen/stdout-path. In legacy platform in open source, it only defined asc1 in dts. There's no asc0 in legacy dts.While in the new platform, asc0 is defined in dts. There's no asc1 in new platform dts. To avoid hard code in driver, alias serial0 is used to unified driver code. Actually only one serial is supported in SoC. aliases {         serial0 = &asc0; }; chosen {     bootargs = "earlycon  clk_ignore_unused";     stdout-path = "serial0"; };