On Wed, Nov 28, 2018 at 6:33 PM Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote: > > On Wed, Nov 28, 2018 at 05:30:01PM +0800, Chen-Yu Tsai wrote: > > Experiments showed that on at least the H3/H5/A64 the RTC's internal > > oscillator also feeds the CPUS mux in the PRCM. > > > > Export this clock through the device tree, instead of having to use > > a dummy fixed-clock device node, for the PRCM to consume. This will > > properly describe the relationship between the clocks. > > > > Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx> > > --- > > Documentation/devicetree/bindings/rtc/sun6i-rtc.txt | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt b/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt > > index 78c4fb472eb7..1bd37faadecb 100644 > > --- a/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt > > +++ b/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt > > @@ -24,7 +24,7 @@ Required properties: > > > > Required properties for new device trees > > - clocks : phandle to the 32kHz external oscillator > > -- clock-output-names : names of the two clock outputs. See below. > > +- clock-output-names : names of the three clock outputs. See below. > > - #clock-cells : must be equal to 1. > > > > The RTC provides the following clocks at the given indices: > > @@ -32,6 +32,7 @@ The RTC provides the following clocks at the given indices: > > - 1: LOSC external output, known as X32KFOUT in the datasheet. > > This clock is not available on the A31 and is deprecated for old > > device trees still using the "allwinner,sun6i-a31-rtc" compatible. > > +- 2: InternalOSC, or internal RC oscillator > > It seems to be required only for a few RTC though (H3, H5 and R40?) IMO there's no harm in exporting it for all SoCs. I still don't know if it's needed for the A31 either. And we don't have documents for the PRCM stuff for any of the SoCs involved. ChenYu
