From: schowdhu@codeaurora.org
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Rob Herring <robh@kernel.org>,
linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org,
devicetree@vger.kernel.org,
Bryan O'Donoghue <pure.logic@nexus-software.ie>,
Greg KH <greg@kroah.com>,
linux-kernel@vger.kernel.org, ckadabi@codeaurora.org,
tsoni@codeaurora.org, bryanh@codeaurora.org,
psodagud@codeaurora.org, satyap@codeaurora.org,
pheragu@codeaurora.org, Rajendra Nayak <rnayak@codeaurora.org>,
Sibi Sankar <sibis@codeaurora.org>,
Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Subject: Re: [PATCH V0 1/7] dt-bindings: connector: Add property for eud type c connector
Date: Thu, 07 Oct 2021 14:55:09 +0530 [thread overview]
Message-ID: <ad4f944d1166882c80a91b3fbbd15fc5@codeaurora.org> (raw)
In-Reply-To: <YVx/U+w8zS6/P6oa@ripper>
On 2021-10-05 22:07, Bjorn Andersson wrote:
> On Tue 05 Oct 06:11 PDT 2021, schowdhu@codeaurora.org wrote:
>
>> On 2021-10-04 22:07, Rob Herring wrote:
>> > On Mon, Oct 04, 2021 at 04:46:19PM +0530, Souradeep Chowdhury wrote:
>> > > Added the property for EUD(Embedded USB Debug) connector.Added
>> > > the "reg" and "interrupts" property which is needed for EUD.
>> >
>> > You are going to need a better explanation of this h/w.
>>
>> Ack. Will update this with the detailed hardware description
>> in the next version.
>>
>> >
>> > >
>> > > Signed-off-by: Souradeep Chowdhury <schowdhu@codeaurora.org>
>> > > ---
>> > > .../devicetree/bindings/connector/usb-connector.yaml | 15
>> > > +++++++++++++++
>> > > 1 file changed, 15 insertions(+)
>> > >
>> > > diff --git
>> > > a/Documentation/devicetree/bindings/connector/usb-connector.yaml
>> > > b/Documentation/devicetree/bindings/connector/usb-connector.yaml
>> > > index 7eb8659..908129f 100644
>> > > --- a/Documentation/devicetree/bindings/connector/usb-connector.yaml
>> > > +++ b/Documentation/devicetree/bindings/connector/usb-connector.yaml
>> > > @@ -30,6 +30,21 @@ properties:
>> > > - const: samsung,usb-connector-11pin
>> > > - const: usb-b-connector
>> > >
>> > > + - items:
>> > > + - enum:
>> > > + - qcom,sc7280-usb-connector-eud
>> > > + - const: qcom,usb-connector-eud
>> > > + - const: usb-c-connector
>> > > +
>> > > + reg:
>> > > + items:
>> > > + - description: EUD Base Register Region
>> > > + - description: EUD Mode Manager Region
>> >
>> > A connector node represents the physical connector on a board. That
>> > can't really be an MMIO peripheral. Maybe you need a node for EUD and
>> > then it should have a connector child node? Don't really know without
>> > understanding this h/w.
>>
>> As per the previous discussion on the EUD, it was agreed upon to map
>> EUD
>> as a type C connector and use Role-Switch to change the USB role
>> instead
>> of extcon interface that was being used previously. The link for the
>> same
>> is as follows:-
>>
>> https://lore.kernel.org/lkml/5db1a666-62ec-c850-6626-ad33d337b452@codeaurora.org/
>>
>
> Not using extcon is the right thing, but perhaps we should make the EUD
> a role_switch provider and client, so that we can describe how it sits
> inbetween the connector and the controller.
>
> That way it has the power to pass through or override requests from the
> upstream role-switcher, based on the status of EUD.
>
>
> That said, I'm still curious to what happens if I renegotiate the roles
> dynamically in a Type-C environment, while enabling EUD. How would the
> device on the other end of the cable know that it's supposed to be a
> host? Or there's simply a reset of the link when this happens?
>
> Thanks,
> Bjorn
Hi Bjorn,
By making EUD Role-Switch provider and client do you mean that
we should have a EUD node which will have a connector node as
child and this connector node will have a port that points towards
the drd role-switch?
So that my device tree node will look like the following in that case
eud@88e0000 {
compatible = "qcom,usb-connector-eud";
reg = <0 0x88e0000 0 0x2000>,
<0 0x88e2000 0 0x1000>;
interrupt-parent = <&pdc>;
interrupts = <11 IRQ_TYPE_LEVEL_HIGH>;
usb_con: connector {
compatible = "usb-c-connector";
label = "USB-C";
port {
eud_usb_output: endpoint {
remote-endpoint = <&eud_usb3_input>;
};
};
};
@usb2 {
dwc3 {
usb-role-switch;
port {
eud_usb3_input: endpoint {
remote-endpoint = <&eud_usb_output>;
};
};
};
Also EUD functions only in device mode, so when the role-switch is done
by the controller
to set the device mode, the PC on the other end becomes the host.
Thanks,
Souradeep
>
>> >
>> > > +
>> > > + interrupts:
>> > > + description:
>> > > + EUD interrupt
>> > > +
>> > > label:
>> > > description: Symbolic name for the connector.
>> > >
>> > > --
>> > > QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
>> > > member
>> > > of Code Aurora Forum, hosted by The Linux Foundation
>> > >
>> > >
next prev parent reply other threads:[~2021-10-07 9:25 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-04 11:16 [PATCH V0 0/7] Add Embedded USB Debugger (EUD) driver Souradeep Chowdhury
2021-10-04 11:16 ` [PATCH V0 1/7] dt-bindings: connector: Add property for eud type c connector Souradeep Chowdhury
2021-10-04 16:37 ` Rob Herring
2021-10-05 13:11 ` schowdhu
2021-10-05 16:37 ` Bjorn Andersson
2021-10-07 9:25 ` schowdhu [this message]
2021-10-12 3:22 ` Bjorn Andersson
2021-11-02 9:20 ` schowdhu
2021-10-04 11:16 ` [PATCH V0 2/7] dt-bindings: usb: dwc3: Update dwc3 properties for EUD connector Souradeep Chowdhury
2021-10-04 15:50 ` Bjorn Andersson
2021-10-05 12:57 ` schowdhu
2021-10-04 11:16 ` [PATCH V0 3/7] usb: dwc3: drd: Register the eud connector child node for dwc3 Souradeep Chowdhury
2021-10-05 4:42 ` kernel test robot
2021-10-05 12:32 ` kernel test robot
2021-10-04 11:16 ` [PATCH V0 4/7] usb: common: eud: Added the driver support for Embedded USB Debugger(EUD) Souradeep Chowdhury
2021-10-04 11:31 ` Greg KH
2021-10-05 12:54 ` schowdhu
2021-10-04 16:42 ` Bjorn Andersson
2021-10-05 7:14 ` Joe Perches
2021-10-05 13:58 ` schowdhu
2021-10-05 13:01 ` schowdhu
2021-10-04 20:08 ` Randy Dunlap
2021-10-05 13:57 ` schowdhu
2021-10-04 11:16 ` [PATCH V0 5/7] arm64: dts: qcom: sc7280: Add EUD connector node Souradeep Chowdhury
2021-10-04 11:16 ` [PATCH V0 6/7] arm64: dts: qcom: sc7280: Set the default dr_mode for usb2 Souradeep Chowdhury
2021-10-04 11:16 ` [PATCH V0 7/7] MAINTAINERS: Add maintainer entry for EUD Souradeep Chowdhury
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