On Fri, Mar 11, 2022 at 08:48:17AM -0600, Rob Herring wrote: > 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]? This seems to be a superset of the previous patchset from Tommaso. Therefore I'd definitley vote for this one if a v2 of it [2] gets merged (it was declined by GregKH because of the e-mail signature and fomatting issues). Until then I assume [1] should be applied as it represents the current master state due to commit 5c2b9c61ae5d (usb: usb251xb: add boost-up property support, 2022-01-28) being already merged. regards;rl [2] https://lore.kernel.org/linux-usb/PH0PR17MB48482AD591AFD471637B16E28E0C9@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > > 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. > > ------------------------------------------------------------------------------------------------------------
