> -----Original Message----- > From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> > Sent: Wednesday, March 22, 2023 4:43 PM > To: Frank Li <frank.li@xxxxxxx> > Cc: devicetree@xxxxxxxxxxxxxxx; festevam@xxxxxxxxx; imx@xxxxxxxxxxxxxxx; > kernel@xxxxxxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; linux- > kernel@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; > shawnguo@xxxxxxxxxx > Subject: Re: [EXT] Re: [PATCH v3 1/3] dt-bindings: usb: cdns-imx8qm: add > imx8qm cdns3 glue bindings > > Caution: EXT Email > > On 22/03/2023 22:40, Frank Li wrote: > > > > > >> -----Original Message----- > >> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> > >> Sent: Wednesday, March 22, 2023 4:38 PM > >> To: Frank Li <frank.li@xxxxxxx> > >> Cc: devicetree@xxxxxxxxxxxxxxx; festevam@xxxxxxxxx; > imx@xxxxxxxxxxxxxxx; > >> kernel@xxxxxxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx; linux-arm- > >> kernel@xxxxxxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; linux- > >> kernel@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; > >> shawnguo@xxxxxxxxxx > >> Subject: Re: [EXT] Re: [PATCH v3 1/3] dt-bindings: usb: cdns-imx8qm: add > >> imx8qm cdns3 glue bindings > >> > >> Caution: EXT Email > >> > >> On 22/03/2023 22:36, Frank Li wrote: > >>> > >>> > >>>> -----Original Message----- > >>>> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> > >>>> Sent: Wednesday, March 22, 2023 4:32 PM > >>>> To: Frank Li <frank.li@xxxxxxx> > >>>> Cc: devicetree@xxxxxxxxxxxxxxx; festevam@xxxxxxxxx; > >> imx@xxxxxxxxxxxxxxx; > >>>> kernel@xxxxxxxxxxxxxx; krzysztof.kozlowski+dt@xxxxxxxxxx; linux-arm- > >>>> kernel@xxxxxxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>; linux- > >>>> kernel@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; > s.hauer@xxxxxxxxxxxxxx; > >>>> shawnguo@xxxxxxxxxx > >>>> Subject: Re: [EXT] Re: [PATCH v3 1/3] dt-bindings: usb: cdns-imx8qm: > add > >>>> imx8qm cdns3 glue bindings > >>>> > >>>> Caution: EXT Email > >>>> > >>>> On 22/03/2023 15:34, Frank Li wrote: > >>>>> > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> > >>>>>> Sent: Wednesday, March 22, 2023 2:32 AM > >>>>>> To: Frank Li <frank.li@nxp. > >>>>>>> + - const: usb3_aclk > >>>>>>> + - const: usb3_ipg_clk > >>>>>>> + - const: usb3_core_pclk > >>>>>>> + > >>>>>>> + assigned-clocks: > >>>>>>> + items: > >>>>>>> + - description: Phandle and clock specifoer of > >>>>>> IMX_SC_PM_CLK_MST_BUS. > >>>>>> > >>>>>> Drop useless pieces so "Phandle and clock specifoer of " and name > the > >>>>>> hardware, not the syntax. > >>>>>> > >>>>>>> + > >>>>>>> + assigned-clock-rates: > >>>>>>> + items: > >>>>>>> + - description: Should be in Range 100 - 600 Mhz. > >>>>>> > >>>>>> That's better but I still do not understand why do you need it in the > >>>>>> bindings. You never actually answered this question. > >>>>> > >>>>> I am not sure 100% sure the reason. > >>>>> I think difference system target's axi bus frequency is difference, > >>>>> And just one time work, needn't software to manage it. > >>>>> Following other driver's code style may be another reason. > >>>> > >>>> That's the reason of heaving it in DTS. But I am asking about bindings. > >>>> You do understand you define here interface? > >>> > >>> I defined here is descript AXI frequency for usb controller. Supposed > >> difference > >>> Platform will have difference working frequency. > >> > >> I don't understand how does this answer my concerns of having it in DT > >> bindings. If you do not add it, you "will have difference working > >> frequency", so what's the point? > > > > For example: imx8qxp, it need set to 250Mhz, i.MX8QM need set to > 200Mhz. > > Maybe future chip can set to 400Mhz. > > And? So as you can see you will still have different frequencies, so > what's the point? What is the benefit? Dunno, maybe we do not understand > each other, because I don't think you are answering my questions at all. Benefit: New chip just need change dts file for the same IP, like change base Reg address and irq number. Your question is: "why need this assigned-clock-rates IMX_SC_PM_CLK_MST_BUS property?" My answer: it is one of hardware property, like reg base address and irq number. If can't match your expectation, can you change another words or provide me an example? > > Best regards, > Krzysztof
