On Wed, Jul 22, 2020 at 07:12:39PM -0700, Thinh Nguyen wrote: > According to USB 3.2 spec, a super-speed-plus device can operate at > gen2x2, gen2x1, or gen1x2. Introduce "num-lanes" and > "lane-speed-mantissa-gbps" properties for devices operating in > super-speed-plus. If the USB controller device supports multiple lanes > at different transfer rate, the user can specify the HW capability via > these properties. > > Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx> > --- > Changes in v2: > - Make "num-lanes" and "lane-speed-mantissa-gbps" common USB properties > > Documentation/devicetree/bindings/usb/generic.txt | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/Documentation/devicetree/bindings/usb/generic.txt b/Documentation/devicetree/bindings/usb/generic.txt > index ba472e7aefc9..a8253da684af 100644 > --- a/Documentation/devicetree/bindings/usb/generic.txt > +++ b/Documentation/devicetree/bindings/usb/generic.txt > @@ -7,6 +7,17 @@ Optional properties: > "low-speed". In case this isn't passed via DT, USB > controllers should default to their maximum HW > capability. > + - num-lanes: tells USB controllers that we want to work up to a certain number > + of lanes. Valid arguments are 1 or 2. Apply if the > + maximum-speed is super-speed-plus. In case this isn't > + passed via DT, the USB controllers should default to > + their maximum HW capability. > + - lane-speed-mantissa-gbps: tells USB controllers that we want the symmetric > + lanes to operate up to a certain rate in Gbps. Valid > + inputs are 5 or 10 (i.e. Gen 1/Gen 2 transfer rate). > + Apply if the maximum-speed is super-speed-plus. In case > + this isn't passed via DT, the USB controllers should > + default to their maximum HW capability. This still leaves 'maximum-speed = "super-speed-plus"' ambiguous. Fix that please. To put it another way, we already have one way to define USB speeds. Don't define a new and different way that only covers a fraction of the possibilities. Rob
