Hi Felipe, On 11/6/2018 3:26 AM, Felipe Balbi wrote: > hi, > > Thinh Nguyen <thinh.nguyen@xxxxxxxxxxxx> writes: >> Add two new device properties to program the reference clock period and >> to enable low power management using the reference clock. This allows a >> higher demand to go in low power for Audio Device Class devices. This >> feature is currently only valid for DWC_usb31 peripheral controller >> v1.80a and higher. >> >> Set "snps,refclk-period-ns" to program the reference clock period. The >> valid input periods are as follow: >> +-------------+-----------------+ >> | Period (ns) | Freq (MHz) | >> +-------------+-----------------+ >> | 25 | 39.7/40 | >> | 41 | 24.4 | >> | 50 | 20 | >> | 52 | 19.2 | >> | 58 | 17.2 | >> | 62 | 16.1 | >> +-------------+-----------------+ >> >> Set "snps,refclk-lpm" to enable low power scheduling of isochronous >> transfers by running SOF/ITP counters using the reference clock. Both >> "snps,dis_u2_susphy_quirk" and "snps,dis_enblslpm_quirk" must not be >> set for this feature to be enabled. >> >> Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx> >> --- >> Documentation/devicetree/bindings/usb/dwc3.txt | 18 ++++++++++++++++++ >> 1 file changed, 18 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt >> index 636630fb92d7..712b344c3a31 100644 >> --- a/Documentation/devicetree/bindings/usb/dwc3.txt >> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt >> @@ -95,6 +95,24 @@ 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: set to program the reference clock period. The valid >> + input periods are as follow: >> + +-------------+-----------------+ >> + | Period (ns) | Freq (MHz) | >> + +-------------+-----------------+ >> + | 25 | 39.7/40 | >> + | 41 | 24.4 | >> + | 50 | 20 | >> + | 52 | 19.2 | >> + | 58 | 17.2 | >> + | 62 | 16.1 | >> + +-------------+-----------------+ >> + - snps,enable-refclk-lpm: set to enable low power scheduling of isochronous >> + transfers by running SOF/ITP counters using the >> + reference clock. Only valid for DWC_usb31 peripheral >> + controller v1.80a and higher. Both >> + "snps,dis_u2_susphy_quirk" and >> + "snps,dis_enblslpm_quirk" must not be set. > sounds like you should rely on clk API here. Then on driver call > clk_get_rate() to computer whatever you need to compute. > There's nothing to compute here. We can simply enable this feature with "snps, enable-refclk-lpm" and the controller will use the default refclk settings. Thinh
