Re: [PATCH v3 11/28] dt-bindings: usb: dwc3: Add snps,num-hc-interrupters definition

[Wesley Cheng]

Hi Rob,

On 3/11/2023 5:40 AM, Rob Herring wrote:
> On Wed, Mar 08, 2023 at 03:57:34PM -0800, Wesley Cheng wrote:
> > Add a new definition for specifying how many XHCI secondary interrupters
> > can be allocated.  XHCI in general can potentially support up to 1024
> > interrupters, which some uses may want to limit depending on how many
> > users utilize the interrupters.
> >
> > Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> > ---
> >   .../devicetree/bindings/usb/snps,dwc3.yaml          | 13 +++++++++++++
> >   1 file changed, 13 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> > index be36956af53b..4e2417191f93 100644
> > --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> > +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> > @@ -359,6 +359,19 @@ properties:
> >       items:
> >         enum: [1, 4, 8, 16, 32, 64, 128, 256]
> >   
> > +  snps,num-hc-interrupters:
> > +    description:
> > +      Defines the maximum number of XHCI host controller interrupters that can
> > +      be supported.  The XHCI host controller has support to allocate multiple
> > +      event rings, which can be assigned to different clients/users.  The DWC3
> > +      controller has a maximum of 8 interrupters.  If this is not defined then
> > +      the value will be defaulted to 1.  This parameter is used only when
> > +      operating in host mode.
>
> Is this an XHCI or DWC3 feature? The former should be added to the XHCI
> binding.

Sorry for the late response...message got routed to a folder I don't 
frequently check...

This is a XHCI feature, but the DWC3 design is built in a way that DWC3 
host initializes the XHCI device and populates the properties associated 
to XHCI dev.

Will update the XHCI yaml as well for non-DWC3 based SoCs.

Thanks
Wesley Cheng