Re: [PATCH V3 5/7] arm64: dts: qcom: sc7280: Add EUD dt node and dwc3 connector

Souradeep Chowdhury
2022-01-17T05:07:34Z

On 1/7/2022 6:23 AM, Bjorn Andersson wrote:
> On Tue 04 Jan 03:58 PST 2022, 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@quicinc.com>
>> ---
>> 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 {
> I think this is backwards.
>
> Iiuc you have dwc3 <-> EUD <-> connector, where the connector typically
> would be represented in relation to a Type-C controller.
>
> So I think this graph should be looking something like:
>
>
> dwc3 {
> ports {
> port {
> dwc3_eud: endpoint {
> remote-endpoint = <&eud_ep>;
> };
> };
> };
> };
>
> eud {
> ports {
> port {
> eud_dwc3: endpoint {
> remote-endpoint = <&dwc3_eud>;
> };
> };
>
> port {
> eud_con: endpoint {
> remote-endpoint = <&con_eud>;
> };
> };
> };
> };
>
> connector {
> compatible = "usb-c-connector";
>
> ports {
> port {
> con_eud: endpoint {
> remote-endpoint = <&eud_con>;
> };
> };
> };
> };
>
> With EUD "forwarding" the role switching requests from the connector, or
> overriding them if the EUD is enabled.
>
> Alternatively the dwc3 would be in a graph with both the eud and the
> connector, but I don't know how to ensure that the EUD decision takes
> precedence over the type-c controllers role request...
>
>
> In the case of us having a type-c controller, such as the pmic_glink,
> the connector node would then be a child of the controller.
Ack. Will align the device tree with this structure.
>
> Regards,
> Bjorn
>
>> + compatible = "qcom,usb-connector-eud",
>> + "usb-c-connector";
>> + ports {
>> + port@0 {
>> + 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
>>