[PATCH 6/8] devicetree: doc: Document ti,timer-parent property

Tony Lindgren tony at atomide.com
Fri Nov 22 12:11:35 EST 2013


* Joel Fernandes <joelf at ti.com> [131122 09:06]:
> On 11/22/2013 09:58 AM, Tony Lindgren wrote:
> > * Joel Fernandes <joelf at ti.com> [131121 18:00]:
> >> +Required properties for system timers (clockevents/clocksource):
> >> +- ti,timer-parent:	System timer's parent mux clock needs to be setup.
> >> +			This is currently hardcoded in code, for DT boot we
> >> +			move this to DT.
> >> +
> > 
> > This can be replaced with just clk_set_rate, or clk_set_parent if needed.
> > Or by having a clocks = <&32k_clk> property in the dmtimer node in the
> > .dts file.
> > 
> >>  Optional properties:
> >>  - ti,timer-alwon:	Indicates the timer is in an alway-on power domain.
> > 
> > Hmm this we may not need, this can probably be deciphered from the compatible
> > flag already?
> 
> I was thinking maybe we can improve the of_clocksource_init matching
> capabilities to match better, not just on compatible but other properties for
> better selection?
> 
> For example, a generic clocksource DT property to say that the timer is in the
> wakeup domain and so should be preferred as the clocksource? Also additional
> properties to force its selection?
> 
> Then we can switch to clocksource_of_init and have it do the selection. Not sure
> if there is such a need or value for other ARM platforms so we may be over
> complicating the framework to handle these quirks. Comments welcomed about it.

Maybe, but so far it seems that it can all be specified in the board specific
.dts file using standard properties, so I'd first play with that.

Regards,

Tony



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