Messages in this thread | | | From | Frank Li <> | Subject | RE: [EXT] Re: [PATCH v3 1/3] dt-bindings: usb: cdns-imx8qm: add imx8qm cdns3 glue bindings | Date | Wed, 22 Mar 2023 22:15:25 +0000 |
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> -----Original Message----- > From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > Sent: Wednesday, March 22, 2023 5:09 PM > To: Frank Li <frank.li@nxp.com> > Cc: devicetree@vger.kernel.org; festevam@gmail.com; imx@lists.linux.dev; > kernel@pengutronix.de; krzysztof.kozlowski+dt@linaro.org; linux-arm- > kernel@lists.infradead.org; dl-linux-imx <linux-imx@nxp.com>; linux- > kernel@vger.kernel.org; robh+dt@kernel.org; s.hauer@pengutronix.de; > shawnguo@kernel.org > 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 22:57, Frank Li wrote: > > > > > >> -----Original Message----- > >> From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > >> Sent: Wednesday, March 22, 2023 4:43 PM > >> To: Frank Li <frank.li@nxp.com> > >> Cc: devicetree@vger.kernel.org; festevam@gmail.com; > imx@lists.linux.dev; > >> kernel@pengutronix.de; krzysztof.kozlowski+dt@linaro.org; linux-arm- > >> kernel@lists.infradead.org; dl-linux-imx <linux-imx@nxp.com>; linux- > >> kernel@vger.kernel.org; robh+dt@kernel.org; s.hauer@pengutronix.de; > >> shawnguo@kernel.org > >> 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@linaro.org> > >>>> Sent: Wednesday, March 22, 2023 4:38 PM > >>>> To: Frank Li <frank.li@nxp.com> > >>>> Cc: devicetree@vger.kernel.org; festevam@gmail.com; > >> imx@lists.linux.dev; > >>>> kernel@pengutronix.de; krzysztof.kozlowski+dt@linaro.org; linux-arm- > >>>> kernel@lists.infradead.org; dl-linux-imx <linux-imx@nxp.com>; linux- > >>>> kernel@vger.kernel.org; robh+dt@kernel.org; > s.hauer@pengutronix.de; > >>>> shawnguo@kernel.org > >>>> 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@linaro.org> > >>>>>> Sent: Wednesday, March 22, 2023 4:32 PM > >>>>>> To: Frank Li <frank.li@nxp.com> > >>>>>> Cc: devicetree@vger.kernel.org; festevam@gmail.com; > >>>> imx@lists.linux.dev; > >>>>>> kernel@pengutronix.de; krzysztof.kozlowski+dt@linaro.org; linux- > arm- > >>>>>> kernel@lists.infradead.org; dl-linux-imx <linux-imx@nxp.com>; > linux- > >>>>>> kernel@vger.kernel.org; robh+dt@kernel.org; > >> s.hauer@pengutronix.de; > >>>>>> shawnguo@kernel.org > >>>>>> 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@linaro.org> > >>>>>>>> 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. > > To remind - the question was: > "That's better but I still do not understand why do you need it in the > bindings." > If you drop it from the bindings the benefit is still there, so what do > you want to prove? > > > > > Your question is: "why need this assigned-clock-rates > IMX_SC_PM_CLK_MST_BUS property?" > > This was the previous thread. Now, related but slightly different, why > do you still need it in the bindings? > > > > My answer: it is one of hardware property, like reg base address and irq > number. > > Sure, it is, I know, and bindings already allow it. Just look at many > DTS and their bindings. Do you see the bindings defining this property? > No. So why do you think it is needed here? I am asking this since like 6 > emails and your answers are not related to bindings at all. > > > > > If can't match your expectation, can you change another words or provide > me an example? > > Yeah, just open several DTS and look for assigned-clock, then open their > bindings and answer - why do you need to add it to the binding but all > other bindings did not have to? If you have the answer, sure, bring > these parts of bindings.
Do you means, Needn't add assigned-clock in binding *document* yaml file? And dts file still can use assigned-clock property.
> > Best regards, > Krzysztof
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