Re: [PATCH v4 10/18] dt-bindings: usb: Convert DWC USB3 bindings to DT schema

Rob Herring
2020-11-30T15:39:17Z

On Wed, Nov 25, 2020 at 1:32 AM Serge Semin
<Sergey.Semin@baikalelectronics.ru> wrote:
>
> On Sat, Nov 21, 2020 at 06:42:28AM -0600, Rob Herring wrote:
> > On Thu, Nov 12, 2020 at 01:29:46PM +0300, Serge Semin wrote:
> > > On Wed, Nov 11, 2020 at 02:14:23PM -0600, Rob Herring wrote:
> > > > On Wed, Nov 11, 2020 at 12:08:45PM +0300, Serge Semin wrote:
> > > > > DWC USB3 DT node is supposed to be compliant with the Generic xHCI
> > > > > Controller schema, but with additional vendor-specific properties, the
> > > > > controller-specific reference clocks and PHYs. So let's convert the
> > > > > currently available legacy text-based DWC USB3 bindings to the DT schema
> > > > > and make sure the DWC USB3 nodes are also validated against the
> > > > > usb-xhci.yaml schema.
> > > > >
> > > > > Note we have to discard the nodename restriction of being prefixed with
> > > > > "dwc3@" string, since in accordance with the usb-hcd.yaml schema USB nodes
> > > > > are supposed to be named as "^usb(@.*)".
> > > > >
> > > > > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > > > >
> > > > > ---
> > > > >
> > > > > Changelog v2:
> > > > > - Discard '|' from the descriptions, since we don't need to preserve
> > > > > the text formatting in any of them.
> > > > > - Drop quotes from around the string constants.
> > > > > - Fix the "clock-names" prop description to be referring the enumerated
> > > > > clock-names instead of the ones from the Databook.
> > > > >
> > > > > Changelog v3:
> > > > > - Apply usb-xhci.yaml# schema only if the controller is supposed to work
> > > > > as either host or otg.
> > > > >
> > > > > Changelog v4:
> > > > > - Apply usb-drd.yaml schema first. If the controller is configured
> > > > > to work in a gadget mode only, then apply the usb.yaml schema too,
> > > > > otherwise apply the usb-xhci.yaml schema.
> > > > > - Discard the Rob'es Reviewed-by tag. Please review the patch one more
> > > > > time.
> > > > > ---
> > > > > .../devicetree/bindings/usb/dwc3.txt | 125 --------
> > > > > .../devicetree/bindings/usb/snps,dwc3.yaml | 303 ++++++++++++++++++
> > > > > 2 files changed, 303 insertions(+), 125 deletions(-)
> > > > > delete mode 100644 Documentation/devicetree/bindings/usb/dwc3.txt
> > > > > create mode 100644 Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> >
> >
> > > > > diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> > > > > new file mode 100644
> > > > > index 000000000000..079617891da6
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> > > > > @@ -0,0 +1,303 @@
> > > > > +# SPDX-License-Identifier: GPL-2.0
> > > > > +%YAML 1.2
> > > > > +---
> > > > > +$id: http://devicetree.org/schemas/usb/snps,dwc3.yaml#
> > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > > +
> > > > > +title: Synopsys DesignWare USB3 Controller
> > > > > +
> > > > > +maintainers:
> > > > > + - Felipe Balbi <balbi@kernel.org>
> > > > > +
> > > > > +description:
> > > > > + This is usually a subnode to DWC3 glue to which it is connected, but can also
> > > > > + be presented as a standalone DT node with an optional vendor-specific
> > > > > + compatible string.
> > > > > +
> > >
> > > > > +allOf:
> > > > > + - $ref: usb-drd.yaml#
> > > > > + - if:
> > > > > + properties:
> > > > > + dr_mode:
> > > > > + const: peripheral
> >
>
> > Another thing, this evaluates to true if dr_mode is not present. You
> > need to add 'required'?
>
> Right. Will something like this do that?

Yes.

>
> + allOf:
> + - $ref: usb-drd.yaml#
> + - if:
> + properties:
> + dr_mode:
> + const: peripheral
> +
> + required:
> + - dr_mode
> + then:
> + $ref: usb.yaml#
> + else
> + $ref: usb-xhci.yaml#
>
> > If dr_mode is otg, then don't you need to apply
> > both usb.yaml and usb-xhci.yaml?
>
> No I don't. Since there is no peripheral-specific DT schema, then the
> only schema any USB-gadget node needs to pass is usb.yaml, which
> is already included into the usb-xhci.yaml schema. So for pure OTG devices
> with xHCI host and gadget capabilities it's enough to evaluate: allOf:
> [$ref: usb-drd.yaml#, $ref: usb-xhci.yaml#]. Please see the
> sketch/ASCII-figure below and the following text for details.

Okay.

Rob