[PATCH v2 6/7] ARM: dts: rockchip: add core rk3288 dtsi

Heiko Stübner heiko at sntech.de
Fri Jul 25 12:45:11 PDT 2014


Am Freitag, 25. Juli 2014, 12:39:06 schrieb Mike Turquette:
> Quoting Doug Anderson (2014-07-24 16:06:34)
> 
> > > +       xin24m: xin24m {
> > > +               compatible = "fixed-clock";
> > > +               clock-frequency = <24000000>;
> > > +               #clock-cells = <0>;
> > > +       };
> > 
> > I'm no expert, but strangely every other .dts seems to have the clocks
> > under a "clocks" node.  That seems to contradict the suggestion made
> > previously that things should not be on the top level, though.
> 
> That usually happens when there is a clock controller (e.g. "clocks")
> that has multiple clock signals coming out of it. Typically this is for
> a clock generator IP within a SoC or other chip.
> 
> However for a single board-level clock such as an osc then it is common
> to put it at a top-level for that board since these can change from
> board to board.

All Rockchip manuals I have (from rk3066 forward) state that the oscillator 
used here must be 24MHz, so I guess it should be ok in the main dtsi files.

In the very unlikely case that a hw designer ignored every piece of 
documentation I guess they could simply reset the clock-frequency value in 
their board dts.

> 
> > Also, _I think_ device tree suggests a more generic name for the node
> > like "oscillator".  You could use "xin24m" as an output name, I think.
> > Mike could correct me if I'm wrong.
> 
> You are correct.

I'll rename it.


Heiko



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