Re: [PATCH V2 6/8] arm64: dts: qcom: sc7280: Add EUD dt node and dwc3 connector

[Souradeep Chowdhury]

On 12/14/2021 1:29 AM, Rob Herring wrote:
> On Thu, Dec 02, 2021 at 03:21:25PM +0530, Souradeep Chowdhury wrote:
> > Add the Embedded USB Debugger(EUD) device tree node. The
> > node contains EUD base register region and EUD mode
> > manager register regions along with the interrupt entry.
> > Also add the connector to EUD which is mapped as the child
> > of dwc3. The connector is attached to EUD via port. Also add
> > the role-switch property to dwc3 node.
> >
> > Signed-off-by: Souradeep Chowdhury <quic_schowdhu@xxxxxxxxxxx>
> > ---
> >   arch/arm64/boot/dts/qcom/sc7280.dtsi | 25 +++++++++++++++++++++++++
> >   1 file changed, 25 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> > index 53a21d0..2d14e5c 100644
> > --- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
> > @@ -1315,6 +1315,18 @@
> >   				phys = <&usb_2_hsphy>;
> >   				phy-names = "usb2-phy";
> >   				maximum-speed = "high-speed";
> > +				usb-role-switch;
> > +				usb_con: eud_usb_connector {
> > +					compatible = "qcom,usb-connector-eud",
> > +						     "usb-c-connector";
> > +					ports {
> > +						port@0 {
> It is already defined that port@0 of the connector is USB HS data. Is
> that the case here? What about the SS lines?

As per the yaml documentation this is to be used for USB HS lines but in 
this case I am using the port to get the connector fwnode from the eud 
driver and then perform the role switch from the connector parent which 
is the dwc3 controller.  Should I update the yaml file to include this 
description?

>  From the description, it sounds like the data path is DWC3 -> EUD ->
> connector. The DT structure doesn't match that.

EUD is an independent QCOM IP , it is a mini usb hub which can only 
function in device mode. That's why it has been mapped as a separate 
device tree node connected to the type c connector via port endpoint to 
perform a role switch when necessary. I have kept EUD and connector at 
the same level as there is no direct data path from EUD to the connector 
and both are at a level below the controller.

> > +							usb2_role_switch: endpoint {
> > +								remote-endpoint = <&eud_ep>;
> > +							};
> > +						};
> > +					};
> > +				};
> >   			};
> >   		};
> >   
> > @@ -1339,6 +1351,19 @@
> >   			interrupts = <GIC_SPI 582 IRQ_TYPE_LEVEL_HIGH>;
> >   		};
> >   
> > +		eud:  eud@88e0000 {
> > +			compatible = "qcom,sc7280-eud","qcom,eud";
> > +			reg = <0 0x88e0000 0 0x2000>,
> > +			      <0 0x88e2000 0 0x1000>;
> > +			interrupt-parent = <&pdc>;
> > +			interrupts = <11 IRQ_TYPE_LEVEL_HIGH>;
> > +			port {
> > +				eud_ep: endpoint {
> > +					remote-endpoint = <&usb2_role_switch>;
> > +				};
> > +			};
> > +		};
> > +
> >   		nsp_noc: interconnect@a0c0000 {
> >   			reg = <0 0x0a0c0000 0 0x10000>;
> >   			compatible = "qcom,sc7280-nsp-noc";
> > --
> > 2.7.4