From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932999AbcAMJWM (ORCPT ); Wed, 13 Jan 2016 04:22:12 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:28829 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932579AbcAMJWD (ORCPT ); Wed, 13 Jan 2016 04:22:03 -0500 Subject: Re: [PATCH v5 5/6] mfd: dt-bindings: add device tree bindings for Hi3519 sysctrl To: Arnd Bergmann References: <1452219400-32478-1-git-send-email-xuejiancheng@huawei.com> <20160112083946.GN19803@x1> <5694C725.6010502@huawei.com> <5675031.hi9rRCqFXs@wuerfel> CC: Lee Jones , , , , , , , , , , , , , , , , , , , , , , , , , , From: xuejiancheng Message-ID: <56961404.1000602@huawei.com> Date: Wed, 13 Jan 2016 17:08:20 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <5675031.hi9rRCqFXs@wuerfel> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.217.211] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020201.56961415.0160,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 0533eaaefda8192e7f99a73e70b68052 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Arnd, On 2016/1/13 6:51, Arnd Bergmann wrote: > On Tuesday 12 January 2016 17:28:05 xuejiancheng wrote: >>>>>>> >>>>>> Not yet. >>>>>> Arnd Bergmann and Rob Herring all suggested adding a specific compatible string >>>>>> with the SOC name. This binding is just used for describing the compatible string now. >>>>>> When more functions on hi3519 SOC are added later, the specific driver will be also >>>>>> needed. >>>>> >>>>> Save this binding until it has more functionality. We here "I'll add >>>>> to this later" all too often. >>>>> >>>> >>>> In the hi3519.dtsi file, there is a system-controller device node described like below: >>>> sysctrl: system-controller@12010000 { >>>> compatible = "hisilicon,hi3519-sysctrl", "syscon"; >>>> reg = <0x12010000 0x1000>; >>>> }; >>>> Do you mean that I should remove "hisilicon,hi3519-sysctrl" and just use "syscon" as the >>>> compatible string?　 >>> >>> Where is this compatible string _used_? >>> >>>> If I want to add "hisilicon,hi3519-sysctrl" for hi3519. where should I put this binding? >>>> Could you give some suggestions? Thank you very much! >>> >>> If you're not using the compatible i.e. the device doesn't have its >>> own driver yet, then there is no need to supply the binding at all, is >>> there? >>> >> >> OK. Thank you. >> > > Sorry for stepping in late here. I still think that every syscon device should > come with a specific compatible string, so we have the option of creating a > driver later on, and I'd like to see a binding document that lists those strings > (which I believe exists here). > > It's really hard to add compatible strings later on, anything else we can > work around by keying off that string and adding a workaround in the kernel. > Is it OK if I put this binding document into the directory "Documentation/devicetree/bindings/arm/hisilicon"? Thank you. > Arnd > > . >