From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v5 5/6] mfd: dt-bindings: add device tree bindings for Hi3519 sysctrl Date: Tue, 12 Jan 2016 23:51:21 +0100 Message-ID: <5675031.hi9rRCqFXs@wuerfel> References: <1452219400-32478-1-git-send-email-xuejiancheng@huawei.com> <20160112083946.GN19803@x1> <5694C725.6010502@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <5694C725.6010502@huawei.com> Sender: linux-kernel-owner@vger.kernel.org To: xuejiancheng Cc: Lee Jones , 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 List-Id: devicetree@vger.kernel.org On Tuesday 12 January 2016 17:28:05 xuejiancheng wrote: > >>>>> > >>>> Not yet. > >>>> Arnd Bergmann and Rob Herring all suggested adding a specific co= mpatible 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 =3D "hisilicon,hi3519-sysctrl", "syscon"; > >> reg =3D <0x12010000 0x1000>; > >> }; > >> Do you mean that I should remove "hisilicon,hi3519-sysctrl" and ju= st use "syscon" as the > >> compatible string?=E3=80=80 > >=20 > > Where is this compatible string _used_? > >=20 > >> If I want to add "hisilicon,hi3519-sysctrl" for hi3519. where shou= ld I put this binding? > >> Could you give some suggestions? Thank you very much! > >=20 > > 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? > >=20 >=20 > OK. Thank you. >=20 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 creati= ng a driver later on, and I'd like to see a binding document that lists thos= e strings (which I believe exists here). It's really hard to add compatible strings later on, anything else we c= an work around by keying off that string and adding a workaround in the ke= rnel. Arnd