[PATCHv9 30/43] ARM: dts: am33xx clock data

[Jan Lübbe]

On Sat, 2013-10-26 at 15:46 +0300, Tero Kristo wrote:
> On 10/26/2013 03:36 AM, Jan Lübbe wrote:
> > On Fri, 2013-10-25 at 18:57 +0300, Tero Kristo wrote:
> >> +       mcasp0_fck: mcasp0_fck {
> >> +               #clock-cells = <0>;
> >> +               compatible = "fixed-factor-clock";
> >> +               clocks = <&sys_clkin_ck>;
> >> +               clock-mult = <1>;
> >> +               clock-div = <1>;
> >> +       };
> >> +
> >> +       mcasp1_fck: mcasp1_fck {
> >> +               #clock-cells = <0>;
> >> +               compatible = "fixed-factor-clock";
> >> +               clocks = <&sys_clkin_ck>;
> >> +               clock-mult = <1>;
> >> +               clock-div = <1>;
> >> +       };
> >
> > What is you use case for these clocks with a fixed factor of 1? Wouldn't
> > it be simpler to just use sys_clkin_ck from the devices?
> 
> This is just kind of a dummy clock node for the driver use, so that it 
> is simpler for them to find their clocks. If these are dropped, the 
> drivers need to know that instead of their old own mcaspX_fck, they now 
> need to directly connect to sys_clkin_ck. This also allows to track 
> usecounts for the clocks better, if you don't have the mcaspX_fck:s for 
> example, you will just have a usecount of 25 for the sys_clkin_ck, but 
> don't really know who is using it. Also, other SoCs most likely have the 
> same name in use, so just to keep the clock data compatible across SoCs.
> 
> These files are also completely autogenerated from the existing clock 
> data under mach-omap2, and these nodes exist there.
> 
> But yea, no hard requirement.

We shouldn't add dummy clocks to simplify debugging, maybe we need some
user tracking in the core clk code?

As there are only few of these factor 1 clocks, I'm fine with keeping
them for consistency here.

Regards,
Jan
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