Hi! On Tue, Aug 13, 2019 at 11:51 PM Rob Herring <robh@xxxxxxxxxx> wrote: > [...] > > +Example: > > + pll { > > + compatible = "mediatek,mt7621-pll"; > > You didn't answer Stephen's question on v1. I thought he was asking why there's a syscon in compatible string. I noticed that the syscon in my previous patch is a copy-paste error from elsewhere and dropped it. > > Based on this binding, there is no way to control/program the PLL. Is > this part of some IP block? The entire section is called "system control" in datasheet and is occupied in arch/mips/ralink/mt7621.c [0] Two clocks provided here is determined by reading some read-only registers in this part. There's another register in this section providing clock gates for every peripherals, but MTK doesn't provide a clock plan in their datasheet. I can't determine corresponding clock frequencies for every peripherals, thus unable to write a working clock driver. > > > + > > + #clock-cells = <1>; > > + clock-output-names = "cpu", "bus"; > > + }; > > -- > > 2.21.0 > > Regards, Chuanhong Guo [0] https://elixir.bootlin.com/linux/latest/source/arch/mips/ralink/mt7621.c#L156