From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH 3/5] dt-bindings: mediatek: Add smi dts binding Date: Tue, 14 Apr 2015 11:06:58 +0100 Message-ID: <20150414100657.GB28709@leverpostej> References: <1425638900-24989-1-git-send-email-yong.wu@mediatek.com> <1425638900-24989-4-git-send-email-yong.wu@mediatek.com> <20150306111338.GD8700@leverpostej> <1429002474.14855.7.camel@mhfsdcap03> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1429002474.14855.7.camel@mhfsdcap03> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Yong Wu Cc: Rob Herring , Joerg Roedel , Matthias Brugger , Robin Murphy , Will Deacon , Daniel Kurtz , Tomasz Figa , Lucas Stach , Catalin Marinas , "linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Sasha Hauer , "srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" List-Id: devicetree@vger.kernel.org On Tue, Apr 14, 2015 at 10:07:54AM +0100, Yong Wu wrote: > Hi Mark, > Thanks very much for review.=20 > About the clock name should be the PoV of _this_ device. Could yo= u > help check below? >=20 > On Fri, 2015-03-06 at 11:13 +0000, Mark Rutland wrote: > > On Fri, Mar 06, 2015 at 10:48:18AM +0000, yong.wu-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org wrot= e: > > > From: Yong Wu > > >=20 > > > This patch add smi binding document. > >=20 > > Please move binding documents to the start of the series. It makes > > things far easier to review. > >=20 > > >=20 > > > Signed-off-by: Yong Wu > > > +++ b/Documentation/devicetree/bindings/soc/mediatek/mediatek,smi= =2Etxt > > > @@ -0,0 +1,17 @@ > > > +SMI hardware block diagram please help check > > > + > > > +Required properties: > > > +- compatible : must be "mediatek,mediatek,mt8173-smi-larb" > >=20 > > Double vendor prefix? > >=20 > > What does "larb" mean? It would be nice for the intorductory paragr= aph > > in this file to explain. > >=20 > > > +- reg : the register of each local arbiter > > > +- clocks : the clocks of each local arbiter > > > +- clock-name: larb_sub*(3 clockes at most) > >=20 > > The names required _must_ be specified here, or clock-names is > > pointless. > >=20 > > The clock names should be from the PoV of _this_ device (i.e. they > > should be the names of the inputs) not from the PoV of the provider > > (i.e. they should not be the names of the outputs from the provider= ). > >=20 > > Mark. > >=20 > After we check with our SMI Designer. Every SMI local arbiter ne= ed > two clocks, which is called APB clocks and SMI clock. > APB clock : Advanced Peripheral Bus Clock. It is the clock for > setting the register of local arbiter. > SMI clock : Smart Multimedia Interface Clock, It is the clock fo= r > transfering the data and command.=20 >=20 > And all the local arbiters need the smi common clock, so we > separate it.=20 >=20 > Then I prepare to design the smi the dtsi like this:=20 >=20 > smi_common:smi@14022000 { > compatible =3D =E2=80=9Cmediate, mt8173-smi=E2=80=9D= ; > reg =3D <0 0x14022000 0 0x1000>; > clocks =3D <&mmsys MM_SMI_COMMON>; > clocks-names =3D =E2=80=9Csmi_common=E2=80=9D; > }; >=20 > larb0: larb@14021000 { > compatible =3D =E2=80=9Cmediate, mt8173-smi-larb=E2=80= =9D; > reg =3D <0 0x14021000 0 0x1000>; > smi =3D <&smi_common>; > clocks =3D <&mmsys MM_SMI_LARB0>,=20 > <&mmsys MM_SMI_LARB0>; > clocks-names =3D =E2=80=9Capb_clk=E2=80=9D, =E2=80=9C= smi_clk=E2=80=9D; > }; >=20 > larb1: larb@16010000 { > compatible =3D =E2=80=9Cmediate, mt8173-smi-larb=E2=80= =9D; > reg =3D <0 0x16010000 0 0x1000>; > smi =3D <&smi_common>; > clocks =3D <&vdecsys VDEC_CKEN>,=20 > <&mmsys VDEC_LARB_CKEN>; > clocks-names =3D =E2=80=9Capb_clk=E2=80=9D, =E2=80=9C= smi_clk=E2=80=9D; > }; > =E2=80=A6=20 > In some local arbiter, the source clock of the APB clock and the > SMI clock may be the same, like larb0. so the two clocks are the same= =2E > And they may be different in other local arbiteres, like larb1. =20 >=20 > If it is designed like this, is it ok? That looks pretty good; the clocks and names on the larb nodes seem sensible. The naming of the "smi_common" clock on the smi_common node looks a bit odd though. Is that really what the clock input is called? Mark. -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html