From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 18 Dec 2018 10:38:58 -0600 From: Rob Herring Subject: Re: [PATCH v2 1/4] usb: dwc3: Add property snps,refclk-period-ns Message-ID: <20181218163858.GA12336@bogus> References: <83adc98adc1760a0fad87d81d171e1dac783e7e5.1544235317.git.thinhn@synopsys.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <83adc98adc1760a0fad87d81d171e1dac783e7e5.1544235317.git.thinhn@synopsys.com> To: Thinh Nguyen Cc: Felipe Balbi , linux-usb@vger.kernel.org, devicetree@vger.kernel.org, Mark Rutland , John Youn List-ID: 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 > --- > 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? Rob