Re: [PATCH 3/5] dt-bindings: mediatek: Add smi dts binding

Yong Wu
2015-04-14T13:55:58Z

On Tue, 2015-04-14 at 21:49 +0800, Yong Wu wrote:
> Hi Mark,
>
> On Tue, 2015-04-14 at 11:06 +0100, Mark Rutland wrote:
> > On Tue, Apr 14, 2015 at 10:07:54AM +0100, Yong Wu wrote:
> > > Hi Mark,
> > > Thanks very much for review.
> > > About the clock name should be the PoV of _this_ device. Could you
> > > help check below?
> > >
> > > On Fri, 2015-03-06 at 11:13 +0000, Mark Rutland wrote:
> > > > On Fri, Mar 06, 2015 at 10:48:18AM +0000, yong.wu@mediatek.com wrote:
> > > > > From: Yong Wu <yong.wu@mediatek.com>
> > > > >
> > > > > This patch add smi binding document.
> > > >
> > > > Please move binding documents to the start of the series. It makes
> > > > things far easier to review.
> > > >
> > > > What does "larb" mean? It would be nice for the intorductory paragraph
> > > > in this file to explain.
> > > >
> > > > > +- reg : the register of each local arbiter
> > > > > +- clocks : the clocks of each local arbiter
> > > > > +- clock-name: larb_sub*(3 clockes at most)
> > > >
> > > > The names required _must_ be specified here, or clock-names is
> > > > pointless.
> > > >
> > > > 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).
> > > >
> > > > Mark.
> > > >
> > > After we check with our SMI Designer. Every SMI local arbiter need
> > > 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 for
> > > transfering the data and command.
> > >
> > > And all the local arbiters need the smi common clock, so we
> > > separate it.
> > >
> > > Then I prepare to design the smi the dtsi like this:
> > >
> > > smi_common:smi@14022000 {
> > > compatible = “mediate, mt8173-smi”;
> > > reg = <0 0x14022000 0 0x1000>;
> > > clocks = <&mmsys MM_SMI_COMMON>;
> > > clocks-names = “smi_common”;
> > > };
> > >
> > > larb0: larb@14021000 {
> > > compatible = “mediate, mt8173-smi-larb”;
> > > reg = <0 0x14021000 0 0x1000>;
> > > smi = <&smi_common>;
> > > clocks = <&mmsys MM_SMI_LARB0>,
> > > <&mmsys MM_SMI_LARB0>;
> > > clocks-names = “apb_clk”, “smi_clk”;
> > > };
> > >
> > > larb1: larb@16010000 {
> > > compatible = “mediate, mt8173-smi-larb”;
> > > reg = <0 0x16010000 0 0x1000>;
> > > smi = <&smi_common>;
> > > clocks = <&vdecsys VDEC_CKEN>,
> > > <&mmsys VDEC_LARB_CKEN>;
> > > clocks-names = “apb_clk”, “smi_clk”;
> > > };
> > > …
> > > 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.
> > > And they may be different in other local arbiteres, like larb1.
> > >
> > > 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.
> After check with DE, the smi_common clock also have its APB clock
> and the smi clock(they have the same clock source).
> And I prepare to delete "_clk" in all the clock-names.
> So it may be like this:
> smi_common:smi@14022000 {
> compatible = “mediate, mt8173-smi”;
> reg = <0 0x14022000 0 0x1000>;
> clocks = <&mmsys MM_SMI_COMMON>,
> <&mmsys MM_SMI_COMMON>;
> clocks-names = “apk”,"smi";
> };
> How about this?
Sorry, I wrote wrong, it should be
clock-names = “apb”,"smi";
>
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