Hi Rob, On 12/18/2018 8:39 AM, Rob Herring wrote: > On Fri, Dec 07, 2018 at 06:27:30PM -0800, Thinh Nguyen wrote: >> This patch introduces property "snps,refclk-period-ns" to inform the >> controller of the reference clock period. If the reference clock period >> is different from the default Core Consultant setting, then this >> property can be set to the reference clock period. >> >> This property does not control the reference clock rate. The controller >> uses this value to perform internal timing calculations that are based >> on the reference clock. >> >> Signed-off-by: Thinh Nguyen <[email protected]> >> --- >> Changes in v2: >> - Split from "usb: dwc3: Add reference clock properties" >> - Revise commit message and property description >> >> Documentation/devicetree/bindings/usb/dwc3.txt | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt >> b/Documentation/devicetree/bindings/usb/dwc3.txt >> index 8e5265e9f658..b7e67edff9b2 100644 >> --- a/Documentation/devicetree/bindings/usb/dwc3.txt >> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt >> @@ -99,6 +99,8 @@ Optional properties: >> this and tx-thr-num-pkt-prd to a valid, non-zero value >> 1-16 (DWC_usb31 programming guide section 1.2.3) to >> enable periodic ESS TX threshold. >> + - snps,refclk-period-ns: if set, this value informs the controller of the >> + reference clock period in nanoseconds. > Shouldn't you be able to retrieve the refclk frequency and then > calculate the period?
The thing is we cannot determine the ref_clk frequency for some devices that don't specify their clocks. So I think we should have an option to inform the controller of the ref_clk period for those devices. Thanks for the the review, Thinh
