[GIT PULL 1/3] rockchip soc changes for 4.5

[Heiko Stübner]

Hi Arnd,

Am Samstag, 12. Dezember 2015, 01:30:17 schrieb Arnd Bergmann:
> On Saturday 05 December 2015 01:53:38 Heiko Stübner wrote:
> > SMP special case for the rk3036 and making sure the arch-timer
> > supply is enabled, similar to the rk3288.
> 
> That is a rather ugly hack, I'd prefer if this could be done cleaner
> rather than duplicated into another place.

I do agree that it is rather ugly :-) .

The general opinion seems to be, that firmware is supposed to make sure this 
timer is enabled and at the time when it got introduced the consensus was to 
not hack up the arch-timer to facilitate this and "just" put it into the soc 
code for the affected cpu.

It seems like the really new rk3228 (quad-core A7 and using psci now) actually 
gets this right now, in having its firmware taking care of this. So it looks 
like this hopefully won't be needed even for future arm32 socs.

I guess I should look at what the new and shiny mainline uboot support does 
for this, but I do think it might actually do it right as well.

So this is really only a hack for flaky vendor-bootloaders.


Which brings me to ...

> Sorry for not seeing this earlier. Can you replace the hardcoded
> RK3036_TIMER_PHYS and RK3288_TIMER6_7_PHYS constants with a DT
> lookup, to make it somewhat less hacky?

I'm not really sure how that is supposed to look like. Technically nothing 
should ever touch that timer, as it will only make the system hang if it gets 
disabled.

We do have a binding for the timer ip block (rockchip,rk3288-timer) but of 
course cannot use that, to make sure the regular timer driver doesn't bind to 
it. So I guess we could do something like:


timer at 200440a0 {
	compatible = "rockchip,arch-timer-supply";
	reg = <0x200440a0 0x20>;
};

try to find this and enable it, but duplicating the hack and spreading it into 
the dts as well somehow doesn't feel like an improvement ;-) .

But I maybe you have a nicer idea on how to do this, than me.


Thanks
Heiko