| Message ID | 20240412080238.134191-3-wefu@redhat.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | RTC: update APM X-Gene RTC driver by adding the pre-scaler support | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | success | |
| robh/patch-applied | success |
On 12/04/2024 16:01:44+0800, wefu@redhat.com wrote: > From: Wei Fu <wefu@redhat.com> > > Add optional property "prescaler" for APM X-Gene RTC. > The clock source on some platform to RTC is NOT 1HZ, > so we need to prescale the clock to make the input clock become 1HZ, > like (32K/prescaler) = 1HZ on the XuanTie TH1520 AP sub-system RTC. > > Signed-off-by: Wei Fu <wefu@redhat.com> > --- > .../devicetree/bindings/rtc/xgene-rtc.txt | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/Documentation/devicetree/bindings/rtc/xgene-rtc.txt b/Documentation/devicetree/bindings/rtc/xgene-rtc.txt > index fd195c358446..25ba8cf0cc31 100644 > --- a/Documentation/devicetree/bindings/rtc/xgene-rtc.txt > +++ b/Documentation/devicetree/bindings/rtc/xgene-rtc.txt > @@ -10,6 +10,9 @@ Required properties: > - #clock-cells: Should be 1. > - clocks: Reference to the clock entry. > > +Optional properties: > +- prescaler: Reference to the Value of Counter Prescaler. What about getting the input clock rate and calculate the needed prescaler instead of having it in the device tree?
diff --git a/Documentation/devicetree/bindings/rtc/xgene-rtc.txt b/Documentation/devicetree/bindings/rtc/xgene-rtc.txt index fd195c358446..25ba8cf0cc31 100644 --- a/Documentation/devicetree/bindings/rtc/xgene-rtc.txt +++ b/Documentation/devicetree/bindings/rtc/xgene-rtc.txt @@ -10,6 +10,9 @@ Required properties: - #clock-cells: Should be 1. - clocks: Reference to the clock entry. +Optional properties: +- prescaler: Reference to the Value of Counter Prescaler. + Example: rtcclk: rtcclk { @@ -26,3 +29,16 @@ rtc: rtc@10510000 { #clock-cells = <1>; clocks = <&rtcclk 0>; }; + +Example XuanTie TH1520 RTC node with Counter Prescaler(prescaler): + +rtc: rtc@fffff40000 { + compatible = "snps,dw-apb-rtc"; + reg = <0xff 0xfff40000 0x0 0x1000>; + interrupts = <74 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&osc_32k>; + clock-names = "osc_32k"; + wakeup-source; + prescaler = <0x8000>; + status = "okay"; +};