From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932589AbcAYO0R (ORCPT ); Mon, 25 Jan 2016 09:26:17 -0500 Received: from mail-wm0-f50.google.com ([74.125.82.50]:36976 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755501AbcAYO0O (ORCPT ); Mon, 25 Jan 2016 09:26:14 -0500 Date: Mon, 25 Jan 2016 14:26:09 +0000 From: Lee Jones To: Arnd Bergmann Cc: xuejiancheng , mturquette@baylibre.com, sboyd@codeaurora.org, p.zabel@pengutronix.de, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, linux@arm.linux.org.uk, khilman@linaro.org, olof@lixom.net, xuwei5@hisilicon.com, haojian.zhuang@linaro.org, zhangfei.gao@linaro.org, bintian.wang@huawei.com, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, yanhaifeng@hisilicon.com, yanghongwei@hisilicon.com, suwenping@hisilicon.com, ml.yang@hisilicon.com, gaofei@hisilicon.com, zhangzhenxing@hisilicon.com, xuejiancheng@hisilicon.com Subject: Re: [PATCH v5 5/6] mfd: dt-bindings: add device tree bindings for Hi3519 sysctrl Message-ID: <20160125142609.GR3368@x1> References: <1452219400-32478-1-git-send-email-xuejiancheng@huawei.com> <20160112083946.GN19803@x1> <5694C725.6010502@huawei.com> <5675031.hi9rRCqFXs@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5675031.hi9rRCqFXs@wuerfel> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 12 Jan 2016, 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. Why is it more difficult (or any different) to add a compatible string later (when it is used) over now (when it is not used)? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog From mboxrd@z Thu Jan 1 00:00:00 1970 From: lee.jones@linaro.org (Lee Jones) Date: Mon, 25 Jan 2016 14:26:09 +0000 Subject: [PATCH v5 5/6] mfd: dt-bindings: add device tree bindings for Hi3519 sysctrl In-Reply-To: <5675031.hi9rRCqFXs@wuerfel> References: <1452219400-32478-1-git-send-email-xuejiancheng@huawei.com> <20160112083946.GN19803@x1> <5694C725.6010502@huawei.com> <5675031.hi9rRCqFXs@wuerfel> Message-ID: <20160125142609.GR3368@x1> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, 12 Jan 2016, 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 at 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. Why is it more difficult (or any different) to add a compatible string later (when it is used) over now (when it is not used)? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog