On Mon, Jul 20, 2020 at 11:01 PM Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> wrote: > > Rob Herring wrote: > > On Thu, Jul 16, 2020 at 02:59:08PM -0700, Thinh Nguyen wrote: > >> Introduce num-lanes and lane-speed-mantissa-gbps for devices operating > >> in super-speed-plus. DWC_usb32 IP supports multiple lanes and can > >> operate in different sublink speeds. Currently the device controller > >> does not have the information of the phy's number of lanes supported. As > >> a result, the user can specify them through these properties if they are > >> different than the default setting. > >> > >> Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx> > >> --- > >> Documentation/devicetree/bindings/usb/dwc3.txt | 9 +++++++++ > >> 1 file changed, 9 insertions(+) > >> > >> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt > >> index d03edf9d3935..4eba0615562f 100644 > >> --- a/Documentation/devicetree/bindings/usb/dwc3.txt > >> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > >> @@ -86,6 +86,15 @@ Optional properties: > >> - snps,quirk-frame-length-adjustment: Value for GFLADJ_30MHZ field of GFLADJ > >> register for post-silicon frame length adjustment when the > >> fladj_30mhz_sdbnd signal is invalid or incorrect. > >> + - snps,num-lanes: set to specify the number of lanes to use. Valid inputs are > >> + 1 or 2. Apply if the maximum-speed is super-speed-plus > >> + only. Default value is 2 for DWC_usb32. For DWC_usb31, > >> + it is always 1 at super-speed-plus. > >> + - snps,lane-speed-mantissa-gbps: set to specify the symmetric lane speed > >> + mantissa in Gbps. Valid inputs are 5 or 10. Apply if > >> + the maximum-speed is super-speed-plus only. Default > >> + value is 10. For DWC_usb31, it's always 10 at > >> + super-speed-plus. > > This is all common USB things and should be common properties (which we > > may already have). > > Sure. For "num-lanes" is simple, any objection if we use > "lane-speed-mantissa-gbps"? Or should we add "lane-speed-exponent"? 'num-lanes' is good as that's what PCIe uses. Document that with 'maximum-speed'. I think 'super-speed-plus' should mean gen 2 10G per lane. Then between num-lanes and maximum-speed you can define all 4 possible rates. Rob
