On Tue, Aug 7, 2018 at 9:08 PM yixin zhu <yixin.zhu@xxxxxxxxxxxxxxx> wrote: > > > > On 8/6/2018 11:18 PM, Rob Herring wrote: > > On Thu, Aug 2, 2018 at 9:03 PM Songjun Wu <songjun.wu@xxxxxxxxxxxxxxx> wrote: > >> From: Yixin Zhu <yixin.zhu@xxxxxxxxxxxxxxx> > >> > >> This patch adds binding documentation for grx500 clock controller. > >> > >> Signed-off-by: YiXin Zhu <yixin.zhu@xxxxxxxxxxxxxxx> > >> Signed-off-by: Songjun Wu <songjun.wu@xxxxxxxxxxxxxxx> > >> --- > >> > >> Changes in v2: > >> - Rewrite clock driver's dt-binding document according to Rob Herring's > >> comments. > >> - Simplify device tree docoment, remove some clock description. > >> > >> .../devicetree/bindings/clock/intel,grx500-clk.txt | 39 ++++++++++++++++++++++ > > Please match the compatible string: intel,grx500-cgu.txt > Will update to use same name. > > > > >> 1 file changed, 39 insertions(+) > >> create mode 100644 Documentation/devicetree/bindings/clock/intel,grx500-clk.txt > >> > >> diff --git a/Documentation/devicetree/bindings/clock/intel,grx500-clk.txt b/Documentation/devicetree/bindings/clock/intel,grx500-clk.txt > >> new file mode 100644 > >> index 000000000000..e54e1dad9196 > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/clock/intel,grx500-clk.txt > >> @@ -0,0 +1,39 @@ > >> +Device Tree Clock bindings for grx500 PLL controller. > >> + > >> +This binding uses the common clock binding: > >> + Documentation/devicetree/bindings/clock/clock-bindings.txt > >> + > >> +The grx500 clock controller supplies clock to various controllers within the > >> +SoC. > >> + > >> +Required properties for clock node > >> +- compatible: Should be "intel,grx500-cgu". > >> +- reg: physical base address of the controller and length of memory range. > >> +- #clock-cells: should be 1. > >> + > >> +Optional Propteries: > >> +- intel,osc-frequency: frequency of the osc clock. > >> +if missing, driver will use clock rate defined in the driver. > > This should use a fixed-clock node instead. > Yes, This is a fixed clock node registered in driver code. > The frequency of the fixed clock is designed to be overwritten by device > tree in case some one verify > clock driver in the emulation platform or in some cases frequency other > than driver defined one is preferred. Emulation platforms often need several hacks that shouldn't be upstream... > These kinds of cases are very rare. But I feel it would be better to > have a way to use customized frequency. > The frequency defined in device tree will overwritten driver defined > frequency before registering fixed-clock node. I don't think you understand what I meant. Add a DT node with "fixed-clock" compatible and have this node refer to it with "clocks" property. The frequency is still in DT, but uses the clock binding. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
