On 02/04/2014 02:11 PM, Mark Brown wrote: > On Tue, Feb 04, 2014 at 01:28:20PM -0600, Nishanth Menon wrote: >> On 02/04/2014 12:22 PM, Mark Brown wrote: > >>> You're assuming that the frequency is a unique key here. That may not >>> be the case, for example two OPPs might have the same CPU clock >>> (assuming that's the frequency you're referring to) but different bus >>> clocking and of course the CPUs or CPU clusters might be individually >>> scalable (this is common in big.LITTLE designs I think). > >> Which is why OPPs are maintained per device, bus OPPs belong to bus >> device (in TI terminology, we'd be talking of cross domain dependency >> here for maintaining asynchronous bridge timing closure constraints - >> but ofcourse, other SoCs may or maynot have such constraints). For >> scaling bus frequency, we already have infrastructure in place - clock >> notifiers - discussion of using that is much deeper topic of it's own. > >> for each processor that is uniquely transitioning, we'd have it's own >> sets of OPPs - the correct representation of the device node is the >> key there. > > I've seen some SoCs characterised over the whole device rather than with > individual parts of the SoC done separately. > Fair enough - however, the data characterized will imply individual processor/bus specific tuples/parameters - the specific parameters might be very unique for SoC, but we have ability to abstract it per SoC already. -- Regards, Nishanth Menon -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
