On 20/03/2023 17:22, Frank Li wrote: >>>>>>> + assigned-clocks: >>>>>>> + items: >>>>>>> + - description: Phandle and clock specifier of >> IMX_SC_PM_CLK_PER. >>>>>>> + - description: Phandle and clock specifoer of >>>> IMX_SC_PM_CLK_MISC. >>>>>>> + - description: Phandle and clock specifoer of >>>>>> IMX_SC_PM_CLK_MST_BUS. >>>>>>> + >>>>>>> + assigned-clock-rates: >>>>>>> + items: >>>>>>> + - description: Must be 125 Mhz. >>>>>>> + - description: Must be 12 Mhz. >>>>>>> + - description: Must be 250 Mhz. >>>>>> >>>>>> I would argue that both properties above are not needed. If your >>>>>> hardware requires fixed frequencies, clock provider can fix them, can't >> it? >>>>> >>>>> Clock provider don't know fixed value and turn on only used by client. >>>> >>>> So maybe fix the clock provider? Or this device driver? Requiring by >>>> binding specific frequencies for every board is a bit redundant. >>> >>> It is not for every boards, it is common for a chip family. Only a place to set >> for >>> QM and QXP. >>> >>> The similar case is network driver, which require a specific frequency at >> clock assign. >>> Generally frequency is fixed, clock source name may change at difference >> chips. >> >> If frequency is always fixed, I don't understand why this is in DT >> bindings. I would even say it should not be in DTS. We don't put into >> DTS properties which are always the same, because otherwise they would >> grow crazy big. > > Although frequency is fixed, clock name may change for difference platform. > > assigned-clocks = <&clk IMX_SC_R_USB_2 IMX_SC_PM_CLK_PER>, > <&clk IMX_SC_R_USB_2 IMX_SC_PM_CLK_MISC>, > <&clk IMX_SC_R_USB_2 IMX_SC_PM_CLK_MST_BUS>; > assigned-clock-rates = <125000000>, <12000000>, <250000000>; > > some platform use IMX_SC_R_USB_2, other platform may use IMX_SC_R_USB_3. This I understand, you wrote it above, so nothing new and my concerns are still there. Best regards, Krzysztof
