On 2 March 2015 at 16:20, Leo Yan <leo....@linaro.org> wrote: > i'm glad to use more general method, let me give more input so that we > can see if can figure out a better way. ;)
And I am glad to hear that :) > 1. From hardware design, during the initialization phase, it will > bind every opps with its corresponding voltage, and pass these related > info to power controller. So later, in kernel the cpufreq driver don't > need manually change the voltage, it will only change the cpu clock > frequency and power controller will automatically handle voltage > related operations. This is similar with TC's SPC implementation. > > So looks likely the cpufreq-dt driver's voltage related ops are > redundant for this case. Its okay, they wouldn't harm. You don't have to specify any regulator in CPUs DT node and the code will not try any fancy stuff :) > 2. For hi6220, it has two clusters but w/t coupled clock domain; after > discussion, the later series SoC will have two clusters with > dedicated clock domain, so we need support these two cases; Its okay.. > if support two clusters, arm_big_little.c is also good option; but it > cannot support coupled clock domain for two clusters; furthermore, the > cpufreq driver also need enable cooling cell so that it can support > thermal framework with cpu cooling device. > > Do u think it's reasonable to apply upper changes to arm_big_little.c? Yes it is, but I want you to use cpufreq-dt instead. It supports multi clusters as well now. > 3. for the file hisi-acpu-cpufreq.c, actually it's common enough; all > register's related operations have been encapsulated in clk driver; > Especially thinking about now have many SoCs have multi-clusters and > only need change the frequency from clk APIs, do u think it's a good > idea to change this driver to be a common driver? Just use cpufreq-dt and you wouldn't be required to make any changes at all.. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
