On Fri, Jan 9, 2015 at 5:47 PM, Hans de Goede <[email protected]> wrote: > Hi, > > > On 09-01-15 10:37, Maxime Ripard wrote: >> >> On Fri, Jan 09, 2015 at 10:11:10AM +0100, Hans de Goede wrote: >>> >>> Hi, >>> >>> On 09-01-15 09:51, Maxime Ripard wrote: >>>> >>>> On Fri, Jan 09, 2015 at 09:36:28AM +0100, Hans de Goede wrote: >>>>> >>>>> Hi, >>>>> >>>>> On 09-01-15 09:30, Maxime Ripard wrote: >>>>>> >>>>>> On Tue, Jan 06, 2015 at 12:56:37AM +0800, wens Tsai wrote: >>>>> >>>>> >>>>> <snip> >>>>> >>>>>>> For sun6i it is somewhat harder. >>>>>> >>>>>> >>>>>> Yep, that version D thing is going to cause us a bit of trouble, but >>>>>> since we don't have any hardware available, I'd say we should ignore >>>>>> it for now. >>>>> >>>>> >>>>> Version D ? I more or less completely missed that, care to explain ? >>>>> >>>>> I guess this is going to impact u-boot too ? >>>> >>>> >>>> I don't think it will, or at least, not for this issue. >>>> >>>> From what we saw in the Allwinner BSPs, the A31 rev D might need >>>> different operating points for cpufreq. >>> >>> >>> Ah, what about the max-speed operating point ? That is being set by >>> u-boot early on, specifically for sun6i / sun8i it sets VDD-CPU to 1.2V >>> and the CPU-clock to 1008MHz. >> >> >> Based on the two samples here: >> >> https://github.com/linux-sunxi/sunxi-boards/blob/master/sys_config/a31/hummingbird_a31.fex#L919 >> and here: >> >> https://github.com/linux-sunxi/sunxi-boards/blob/master/sys_config/a31/mele_i7.fex#L1436 >> >> The voltage always seem lower for each OPP. So I guess if you use the >> voltages from the pre-rev-D OPPs, you'd be fine. >> >>>> It's not really an issue per-se, but supporting both pre-rev-D and >>>> post-rev-D will need to have a bit of thoughts. >>> >>> >>> Hmm, tricky. What if we add a second, soc-specific, compatible to the >>> cpu nodes which contains the cpu-revision, and then have 2 nodes >>> for each cpu, with either one (or both) with status = "disabled"; and >>> then on early board init detect the revision and enable the right cpu >>> nodes ? >> >> >> I was more thinking to feed the OPPs directly from the code in >> mach-sunxi if we detect a rev-D. I don't really know what would be the >> side effects of playing with the CPU nodes like that. > > > True (wrt side-effects), but having the OPPs defined in code, rather then > in the dts seems wrong to me. Maybe for sun6i we need to define the OPPs > in a separate dt-node (one per revision) and have mach-sunxi populate > the cpu node with the OPPs for the right revision ?
That was kind of what I had in mind when I started. May need some changes to cpufreq-dt driver. It currently loads OPPs from the default bindings unconditionally. Not sure if changing this would break anyone else. ChenYu -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
