Hi Krzysztof, On Fri, 2022-04-08 at 10:17 +0200, Krzysztof Kozlowski wrote: > On 08/04/2022 07:21, Johnson Wang wrote: > > Add devicetree binding of mtk cci devfreq on MediaTek SoC. > > > > Thank you for your patch. There is something to discuss/improve. > > > Signed-off-by: Johnson Wang <johnson.wang@xxxxxxxxxxxx> > > Signed-off-by: Jia-Wei Chang <jia-wei.chang@xxxxxxxxxxxx> > > --- > > .../devicetree/bindings/devfreq/mtk-cci.yaml | 72 > > +++++++++++++++++++ > > 1 file changed, 72 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/devfreq/mtk- > > cci.yaml > > Filename with vendor prefix, so something like: > > mediatek,cci.yaml Thank you for your review. I will take your advice in the next version. > > Also please put it in the "interconnect" directory. > I don't really know about "interconnect". However, it looks like a Linux framework about data transfer and "NoC". While this cci driver is more like a power managment which is responsible for adjusting voltages and frequencies. In my opinion, "devfreq" should be more suitable. Please correct me if my understanding is wrong. > > diff --git a/Documentation/devicetree/bindings/devfreq/mtk-cci.yaml > > b/Documentation/devicetree/bindings/devfreq/mtk-cci.yaml > > new file mode 100644 > > index 000000000000..ef4ea951025c > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/devfreq/mtk-cci.yaml > > @@ -0,0 +1,72 @@ > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: > > https://urldefense.com/v3/__http://devicetree.org/schemas/devfreq/mtk-cci.yaml*__;Iw!!CTRNKA9wMg0ARbw!yd_wfLu2nSv0GsJZOGP1S8McsGD9A2SC4Qe0Xg1wEb_yEMVcqHRqdvs-M8YKOGckaagO$ > > > > +$schema: > > https://urldefense.com/v3/__http://devicetree.org/meta-schemas/core.yaml*__;Iw!!CTRNKA9wMg0ARbw!yd_wfLu2nSv0GsJZOGP1S8McsGD9A2SC4Qe0Xg1wEb_yEMVcqHRqdvs-M8YKOERouJvA$ > > > > + > > +title: MediaTek Cache Coherent Interconnect (CCI) frequency and > > voltage scaling > > + > > +maintainers: > > + - Jia-Wei Chang <jia-wei.chang@xxxxxxxxxxxx> > > + > > +description: | > > + MediaTek Cache Coherent Interconnect (CCI) uses the software > > devfreq module > > Do not reference software implementation (devfreq). I will modify it in the next version. > > > + to scale the clock frequency and adjust the voltage. MediaTek > > CCI shares > > + the same power supplies with CPU, so the scheduling involves > > with CPUfreq. > > The same - cpufreq. > > Instead, focus on the hardware, what do you describe here? I will focus on hardware description in the next version. > > > + > > +properties: > > + compatible: > > + enum: > > + - mediatek,mt8183-cci > > + - mediatek,mt8186-cci > > + > > + clocks: > > + items: > > + - description: > > + The multiplexer for clock input of CPU cluster. > > + - description: > > + A parent of "cpu" clock which is used as an intermediate > > clock source > > + when the original CPU is under transition and not stable > > yet. > > + > > + clock-names: > > + items: > > + - const: cci > > + - const: intermediate > > + > > + operating-points-v2: > > + description: > > + For details, please refer to > > + Documentation/devicetree/bindings/opp/opp-v2.yaml > > No need for description. Just "operating-points-v2: true". > > "opp-table:true" could stay. My previous comment about its removal > was a > wrong advice, because opp-table is used for a table being a children > of > this device node. > > Best regards, > Krzysztof I will remove it and add "opp-table:true"(also example) in the next version. Thanks. BRs, Johnson Wang
