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

Am Freitag, 25. Juli 2014, 12:39:06 schrieb Mike Turquette:

Quoting Doug Anderson (2014-07-24 16:06:34)

quoted

quoted

+       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.

quoted

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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