On Fri, Mar 11, 2022 at 12:09:42PM +0000, Neumann, Bastian wrote: > This patch adds devicetree documentation for signal boosting properties. > > Signed-off-by: Bastian Neumann <bastian.neumann@xxxxxxxxxxxxxxxxxx> > --- > .../devicetree/bindings/usb/usb251xb.txt | 22 +++++++++++++++++++ > 1 file changed, 22 insertions(+) A popular feature all the sudden. Which one are we supposed to apply? This one or this[1]? Rob [1] https://lore.kernel.org/all/20220306184720.5350-1-tomm.merciai@xxxxxxxxx/ > > diff --git a/Documentation/devicetree/bindings/usb/usb251xb.txt b/Documentation/devicetree/bindings/usb/usb251xb.txt > index 1a934eab175e..538ae49fc31d 100644 > --- a/Documentation/devicetree/bindings/usb/usb251xb.txt > +++ b/Documentation/devicetree/bindings/usb/usb251xb.txt > @@ -68,6 +68,26 @@ Optional properties : > - swap-dx-lanes : Specifies the ports which will swap the differential-pair > (D+/D-), default is not-swapped. > > +Electrical signal boosting > +The controller supplies a "boosting" functionality to drive up the USB > +electrical signals. This could result in non-USB compliant parameters > +(one example would be J/K level test). This should be <0x00> unless specific > +implementation issues requiew additional signal boosting to correct for deraded > +USB signaling levels: > + - <0x00> : Normal electrical drive strength (no boost) > + - <0x01> : Elevated drive strength low (~4% boost) > + - <0x02> : Elevated drive strength medium (~8% boost) > + - <0x03> : Elevated drive strength high (~12% boost) > + > + - boost-up : USB electrical signaling drive strength boost for upstream port. > + - boost-1 : USB electrical signaling drive strength boost for port 1. > + - boost-2 : USB electrical signaling drive strength boost for port 2. > + - boost-3 : USB electrical signaling drive strength boost for port 3. > + - boost-4 : USB electrical signaling drive strength boost for port 4. > + - boost-5 : USB electrical signaling drive strength boost for port 5. > + - boost-6 : USB electrical signaling drive strength boost for port 6. > + - boost-7 : USB electrical signaling drive strength boost for port 7. > + > Examples: > usb2512b@2c { > compatible = "microchip,usb2512b"; > @@ -86,4 +106,6 @@ Examples: > serial = "1234567890A"; > /* correct misplaced usb connectors on port 1,2 */ > swap-dx-lanes = <1 2>; > + boost-up = <0x00>; /* no boost for upstream port */ > + boost-1 = <0x02>; /* medium boost on port 1 */ > }; > -- > 2.30.2 > > > ----------------------------------------------------------------------------------------------------------- > Sirona Dental Systems GmbH > Sitz der Gesellschaft / registered address: Fabrikstraße 31, 64625 Bensheim > Registergericht / court of registry: Amtsgericht Darmstadt, HRB 24948 > Geschäftsführer / Managing Director: Dr. Cord Stähler, Jan Siefert, Rainer Raschke > Aufsichtsratsvorsitzender / Chairman of the Supervisory Board: Dr. Alexander Voelcker > > ----------------------------------------------------------------------------------------------------------- > > > Diese E-Mail ist ausschliesslich fuer den angesprochenen Adressaten > bestimmt und kann vertrauliche Informationen beinhalten. > -- > This e-mail is intended only for the designated recipient(s). It may > contain confidential or proprietary information. > ------------------------------------------------------------------------------------------------------------
