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

Yong Wu
2015-04-14T13:50:06Z

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?