Hi, Daniel > On 23/06/2019 14:38, Anson.Huang@xxxxxxx wrote: > > From: Anson Huang <Anson.Huang@xxxxxxx> > > > > Systems which use platform driver model for clock driver require the > > clock frequency to be supplied via device tree when system counter > > driver is enabled. > > > > This is necessary as in the platform driver model the of_clk > > operations do not work correctly because system counter driver is > > initialized in early phase of system boot up, and clock driver using > > platform driver model is NOT ready at that time, it will cause system > > counter driver initialization failed. > > > > Add the optinal clock-frequency to the device tree bindings of the NXP > > system counter, so the frequency can be handed in and the of_clk > > operations can be skipped. > > > > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx> > > --- > > Changes since V1: > > - improve commit log, no content change. > > --- > > Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt | 6 > > ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git > > a/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt > > b/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt > > index d576599..c9907a0 100644 > > --- a/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt > > +++ b/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt > > @@ -14,6 +14,11 @@ Required properties: > > - clocks : Specifies the counter clock. > > - clock-names: Specifies the clock's name of this module > > > > +Optional properties: > > + > > +- clock-frequency : Specifies system counter clock frequency and indicates > system > > + counter driver to skip clock operations. > > + > > Shouldn't it be required and mutually exclusive with clocks/clock-names? > Yes, make sense, I ever thought about it when doing this patch, but eventually I picked the optional...will fix it in next version. Thanks, Anson > > Example: > > > > system_counter: timer@306a0000 { > > @@ -22,4 +27,5 @@ Example: > > clocks = <&clk_8m>; > > clock-names = "per"; > > interrupts = <GIC_SPI 47 IRQ_TYPE_LEVEL_HIGH>; > > + clock-frequency = <8333333>; > > }; > > > >