Messages in this thread | | | Date | Thu, 23 Mar 2023 07:33:42 +0100 | Subject | Re: [EXT] Re: [PATCH v3 1/3] dt-bindings: usb: cdns-imx8qm: add imx8qm cdns3 glue bindings | From | Krzysztof Kozlowski <> |
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On 22/03/2023 23:15, Frank Li wrote: > > >> -----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.
Yes, I said it many times already...
Best regards, Krzysztof
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