On Thu, 2022-03-24 at 11:33 +0100, Krzysztof Kozlowski wrote: > On 24/03/2022 10:38, Jia-Wei Chang wrote: > > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq- > > > > mediatek.yaml > > > > b/Documentation/devicetree/bindings/cpufreq/cpufreq- > > > > mediatek.yaml > > > > new file mode 100644 > > > > index 000000000000..584946eb3790 > > > > --- /dev/null > > > > +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq- > > > > mediatek.yaml > > > > @@ -0,0 +1,131 @@ > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > > +%YAML 1.2 > > > > +--- > > > > +$id: > > > > https://urldefense.com/v3/__http://devicetree.org/schemas/cpufreq/cpufreq-mediatek.yaml*__;Iw!!CTRNKA9wMg0ARbw!xbKG4TgD0MRpMLyGJVBZEGpZFrNOclrcxOCx_APKo5Nmg8nF2x5PcBdE0unvL2NdpChkMA$ > > > > > > > > +$schema: > > > > https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!xbKG4TgD0MRpMLyGJVBZEGpZFrNOclrcxOCx_APKo5Nmg8nF2x5PcBdE0unvL2O8T_oxCQ$ > > > > > > > > + > > > > +title: Mediatek CPUFREQ driver Device Tree Bindings > > > > > > Please remove "driver Device Tree Bindings" because the title > > > should > > > describe the hardware. Therefore it could be something like > > > "Mediatek > > > SoC CPU frequency and voltage scaling". > > > > Thanks for your suggestion of title. > > Or should I use the origin title "Binding for MediaTek's CPUFreq > > driver"? > > Mediatek CPUFREQ > or > Mediatek CPU frequency scaling Ok, I will choose one of it. > > > > > > > > > How is it related to cpufreq-mediatek-hw.yaml? The names/title > > > look > > > unfortunately too similar. > > > > No, mediatek-cpufreq is performing in kernel driver rather than on > > hardware. > > On the other hand, mediatek-cpufreq-hw is performing on hardware. > > That's why "hw" is present in its name. > > Unfortunately, I do not get it. The bindings are only about hardware, > so > how bindings could be about CPU frequency scaling not in hardware? Sorry, let me correct my statements. For mediatek-cpufreq here, the required hardware are clock and regulator which have to be under control of mediatek-cpufreq. That's the reason why it needs bindings. mediatek-cpufreq scales up and down voltage and frequency via kernel framework of clock and regulator, however, mediatek-cpufreq-hw delegate the voltage and frequency control to a hardware agent instead. > > > > > > > > > In general this does not look like proper bindings (see also > > > below > > > lack > > > of compatible). Bindings describe the hardware, so what is > > > exactly > > > the > > > hardware here? > > > > Except for SoC, there's no requirement of hardware binding for > > mediatek-cpufreq. > > mediatek-cpufreq recognizes the compatible of Mediatek SoC while > > probing. > > What is the hardware here? If there is no requirement for bindings > for > mediate-cpufreq, why do we have this patch here? Sorry, that's my mistake. Clock and regulator are required hardware for mediatek-cpufreq. > > > > > > > > > > + > > > > +maintainers: > > > > + - Jia-Wei Chang <jia-wei.chang@xxxxxxxxxxxx> > > > > + > > > > +description: | > > > > + CPUFREQ is used for scaling clock frequency of CPUs. > > > > + The module cooperates with CCI DEVFREQ to manage frequency > > > > for > > > > some Mediatek > > > > + SoCs. > > > > + > > > > +properties: > > > > > > How is this schema going to be applied? I don't see here select > > > neither > > > compatible. > > > > As mentioned above, only compatible of SoC is required for > > mediatek- > > cpufreq. > > It does not answer my questions. How the schema is going to be > applied? Currently, we do use compatible of SoC to probe mediatek-cpufreq. If the better way is using clock and regulator opp, do you have a suggestion to approach that? I mean I can't find a good example from other vendors trying to do that way. Or maybe I miss something? > > > Best regards, > Krzysztof
