On 28/02/2022 07:31, qinjian[覃健] wrote: >>> +examples: >>> + - | >>> + clkc: clock-controller@9c000000 { >>> + compatible = "sunplus,sp7021-clkc"; >>> + #clock-cells = <1>; >>> + reg = <0x9c000000 0x280>; >>> + clocks = <&extclk>, <&clkc PLL_SYS>; >> >> Except the warning pointed out by Rob's bot, it looks like you feed this >> clock-controller with a clock from itself. Is there a point to express >> it in DTS at all? > > Yes, pllsys is an internal clock, but it also as a parent clock for some other > clocks in this clock-controller. What is the point to express it in DTS? Usually such internal parent-child relation is described in the driver. And how does it even work? How can you get a clock from a device before you registered that device? Best regards, Krzysztof