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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS 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 003EFC04EB9 for ; Mon, 3 Dec 2018 07:43:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4FFA2147C for ; Mon, 3 Dec 2018 07:43:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4FFA2147C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=socionext.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 S1725868AbeLCHnC (ORCPT ); Mon, 3 Dec 2018 02:43:02 -0500 Received: from mx.socionext.com ([202.248.49.38]:48441 "EHLO mx.socionext.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725829AbeLCHnB (ORCPT ); Mon, 3 Dec 2018 02:43:01 -0500 Received: from unknown (HELO iyokan-ex.css.socionext.com) ([172.31.9.54]) by mx.socionext.com with ESMTP; 03 Dec 2018 16:42:57 +0900 Received: from mail.mfilter.local (m-filter-1 [10.213.24.61]) by iyokan-ex.css.socionext.com (Postfix) with ESMTP id 3DC5A60062; Mon, 3 Dec 2018 16:42:57 +0900 (JST) Received: from 172.31.9.53 (172.31.9.53) by m-FILTER with ESMTP; Mon, 3 Dec 2018 16:42:57 +0900 Received: from yuzu.css.socionext.com (yuzu [172.31.8.45]) by iyokan.css.socionext.com (Postfix) with ESMTP id B222240394; Mon, 3 Dec 2018 16:42:56 +0900 (JST) Received: from [127.0.0.1] (unknown [10.213.119.83]) by yuzu.css.socionext.com (Postfix) with ESMTP id 91700120304; Mon, 3 Dec 2018 16:42:56 +0900 (JST) Subject: Re: [PATCH 02/14] dt-bindings: soc: milbeaut: Add Milbeaut trampoline description To: Stephen Boyd , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Cc: Michael Turquette , Rob Herring , Mark Rutland , Greg Kroah-Hartman , Daniel Lezcano , Thomas Gleixner , Russell King , Jiri Slaby , Masami Hiramatsu , Jassi Brar References: <1542589274-13878-1-git-send-email-sugaya.taichi@socionext.com> <1542589274-13878-3-git-send-email-sugaya.taichi@socionext.com> <154337047410.88331.9696178601340675631@swboyd.mtv.corp.google.com> <154356579701.88331.5043467509900444879@swboyd.mtv.corp.google.com> From: "Sugaya, Taichi" Message-ID: Date: Mon, 3 Dec 2018 16:42:56 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <154356579701.88331.5043467509900444879@swboyd.mtv.corp.google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2018/11/30 17:16, Stephen Boyd wrote: > Quoting Sugaya, Taichi (2018-11-29 04:24:51) >> On 2018/11/28 11:01, Stephen Boyd wrote: >>> Quoting Sugaya Taichi (2018-11-18 17:01:07) >>>> create mode 100644 Documentation/devicetree/bindings/soc/socionext/socionext,m10v.txt >>>> >>>> diff --git a/Documentation/devicetree/bindings/soc/socionext/socionext,m10v.txt b/Documentation/devicetree/bindings/soc/socionext/socionext,m10v.txt >>>> new file mode 100644 >>>> index 0000000..f5d906c >>>> --- /dev/null >>>> +++ b/Documentation/devicetree/bindings/soc/socionext/socionext,m10v.txt >>>> @@ -0,0 +1,12 @@ >>>> +Socionext M10V SMP trampoline driver binding >>>> + >>>> +This is a driver to wait for sub-cores while boot process. >>>> + >>>> +- compatible: should be "socionext,smp-trampoline" >>>> +- reg: should be <0x4C000100 0x100> >>>> + >>>> +EXAMPLE >>>> + trampoline: trampoline@0x4C000100 { >>> Drop the 0x part of unit addresses. >> >> Okay. >> >> >>>> + compatible = "socionext,smp-trampoline"; >>>> + reg = <0x4C000100 0x100>; >>> Looks like a software construct, which we wouldn't want to put into DT >>> this way. DT doesn't describe drivers. >> We would like to use this node only getting the address of the >> trampoline area >> in which sub-cores wait.  (They have finished to go to this area in previous >> bootloader process.) > > Is this area part of memory, or a special SRAM? If it's part of memory, > I would expect this node to be under the reserved-memory node and > pointed to by some other node that uses this region. Could even be the > CPU nodes. Yes, 0x4C000100 is a part of memory under the reserved-memory node. So we would like to use the SRAM ( allocated 0x00000000 ) area instead. BTW, sorry, the trampoline address of this example is simply wrong. We were going to use a part of the SRAM from the beginning. > >> >> So should we embed the constant value in source codes instead of getting >> from >> DT because the address is constant at the moment? Or is there other >> approach? >> > > If it's constant then that also works. Why does it need to come from DT > at all then? We think it is not good to embed constant value in driver codes and do not have another way... Are there better ways? Thanks Sugaya Taichi >