Hi, On 24-07-15 14:49, Thomas Kaiser wrote:
Hi, Timo wrote:I think what Maxime was trying to say is, that while all of your boards support Cpufreq, only the Cubietruck supports voltage scaling because only Cubietruck has the power regulator nodes defined in it's dts file (just have a look at the last lines of the Cubitruck dts file and compare that to the dts file, let's say, for Bananapi). On the other boards, the frequency is scaled, but the voltage always stays at 1.4V as set in U-Boot (that means the voltages in the cpufreq operating points are not used on these boards). At least that's what I understand after a recent email axchange with Chen-Yu Tsai.Ah, now I think I understand. You're talking about these lines here? https://github.com/RobertCNelson/u-boot/blob/master/arch/arm/dts/sun7i-a20-cubietruck.dts#L244-L269 So while using CONFIG_REGULATOR_AXP20X=y will bring working cpufreq support to the cubietruck, shouldn't adding these lines to the device trees of the other 5 A20 devices enable CPU voltage scaling there?
There is slightly more to it then those 5 lines, but yes we should enable voltage scaling on more boards. This mostly requires someone to simply just do the work. I've a workshop on dts this weekend at our localhacker space and the plan is for the people attending to get some handson experience by them doing this work (amongst other things) :) Regards, Hans