Message-ID: <ly5j2eodrajifosz34nokia4zckfftakz5253d2h6kd2cxjoq3@yrquqgpnvhp6>
Date: Tue, 2 Sep 2025 05:34:27 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Krishna Kurapati PSSNV <krishna.kurapati@....qualcomm.com>
Cc: Monish Chunara <quic_mchunara@...cinc.com>,
        Sushrut Shree Trivedi <quic_sushruts@...cinc.com>,
        Wasim Nazir <wasim.nazir@....qualcomm.com>,
        Ulf Hansson <ulf.hansson@...aro.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>,
        Richard Cochran <richardcochran@...il.com>, kernel@....qualcomm.com,
        linux-mmc@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        netdev@...r.kernel.org,
        Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>,
        Nirmesh Kumar Singh <quic_nkumarsi@...cinc.com>,
        Mohd Ayaan Anwar <quic_mohdayaa@...cinc.com>,
        Dikshita Agarwal <quic_dikshita@...cinc.com>,
        Vishal Kumar Pal <quic_vispal@...cinc.com>
Subject: Re: [PATCH 3/5] arm64: dts: qcom: lemans-evk: Extend peripheral and
 subsystem support

On Mon, Sep 01, 2025 at 01:02:15PM +0530, Krishna Kurapati PSSNV wrote:
> 
> 
> On 8/29/2025 9:54 PM, Dmitry Baryshkov wrote:
> > On Fri, Aug 29, 2025 at 07:50:57PM +0530, Monish Chunara wrote:
> > > On Thu, Aug 28, 2025 at 04:30:00PM +0300, Dmitry Baryshkov wrote:
> > > > On Thu, Aug 28, 2025 at 06:38:03PM +0530, Sushrut Shree Trivedi wrote:
> > > > > 
> > > > > On 8/27/2025 7:05 AM, Dmitry Baryshkov wrote:
> > > > > > On Tue, Aug 26, 2025 at 11:51:02PM +0530, Wasim Nazir wrote:
> > > > > > > Enhance the Qualcomm Lemans EVK board file to support essential
> > > > > > > peripherals and improve overall hardware capabilities, as
> > > > > > > outlined below:
> > > > > > >     - Enable GPI (Generic Peripheral Interface) DMA-0/1/2 and QUPv3-0/2
> > > > > > >       controllers to facilitate DMA and peripheral communication.
> > > > > > >     - Add support for PCIe-0/1, including required regulators and PHYs,
> > > > > > >       to enable high-speed external device connectivity.
> > > > > > >     - Integrate the TCA9534 I/O expander via I2C to provide 8 additional
> > > > > > >       GPIO lines for extended I/O functionality.
> > > > > > >     - Enable the USB0 controller in device mode to support USB peripheral
> > > > > > >       operations.
> > > > > > >     - Activate remoteproc subsystems for supported DSPs such as Audio DSP,
> > > > > > >       Compute DSP-0/1 and Generic DSP-0/1, along with their corresponding
> > > > > > >       firmware.
> > > > > > >     - Configure nvmem-layout on the I2C EEPROM to store data for Ethernet
> > > > > > >       and other consumers.
> > > > > > >     - Enable the QCA8081 2.5G Ethernet PHY on port-0 and expose the
> > > > > > >       Ethernet MAC address via nvmem for network configuration.
> > > > > > >       It depends on CONFIG_QCA808X_PHY to use QCA8081 PHY.
> > > > > > >     - Add support for the Iris video decoder, including the required
> > > > > > >       firmware, to enable video decoding capabilities.
> > > > > > >     - Enable SD-card slot on SDHC.
> > > > > > > 
> > > > > > > Co-developed-by: Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>
> > > > > > > Signed-off-by: Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>
> > > > > > > Co-developed-by: Sushrut Shree Trivedi <quic_sushruts@...cinc.com>
> > > > > > > Signed-off-by: Sushrut Shree Trivedi <quic_sushruts@...cinc.com>
> > > > > > > Co-developed-by: Nirmesh Kumar Singh <quic_nkumarsi@...cinc.com>
> > > > > > > Signed-off-by: Nirmesh Kumar Singh <quic_nkumarsi@...cinc.com>
> > > > > > > Co-developed-by: Krishna Kurapati <krishna.kurapati@....qualcomm.com>
> > > > > > > Signed-off-by: Krishna Kurapati <krishna.kurapati@....qualcomm.com>
> > > > > > > Co-developed-by: Mohd Ayaan Anwar <quic_mohdayaa@...cinc.com>
> > > > > > > Signed-off-by: Mohd Ayaan Anwar <quic_mohdayaa@...cinc.com>
> > > > > > > Co-developed-by: Dikshita Agarwal <quic_dikshita@...cinc.com>
> > > > > > > Signed-off-by: Dikshita Agarwal <quic_dikshita@...cinc.com>
> > > > > > > Co-developed-by: Monish Chunara <quic_mchunara@...cinc.com>
> > > > > > > Signed-off-by: Monish Chunara <quic_mchunara@...cinc.com>
> > > > > > > Co-developed-by: Vishal Kumar Pal <quic_vispal@...cinc.com>
> > > > > > > Signed-off-by: Vishal Kumar Pal <quic_vispal@...cinc.com>
> > > > > > > Signed-off-by: Wasim Nazir <wasim.nazir@....qualcomm.com>
> > > > > > > ---
> > > > > > >    arch/arm64/boot/dts/qcom/lemans-evk.dts | 387 ++++++++++++++++++++++++++++++++
> > > > > > >    1 file changed, 387 insertions(+)
> > > > > > > 
> > > > > > 
> > > > > > > @@ -356,6 +720,29 @@ &ufs_mem_phy {
> > > > > > >    	status = "okay";
> > > > > > >    };
> > > > > > > +&usb_0 {
> > > > > > > +	status = "okay";
> > > > > > > +};
> > > > > > > +
> > > > > > > +&usb_0_dwc3 {
> > > > > > > +	dr_mode = "peripheral";
> > > > > > Is it actually peripheral-only?
> > > > > 
> > > > > Hi Dmitry,
> > > > > 
> > > > > HW supports OTG mode also, but for enabling OTG we need below mentioned
> > > > > driver changes in dwc3-qcom.c :
> > > > 
> > > > Is it the USB-C port? If so, then you should likely be using some form
> > > > of the Type-C port manager (in software or in hardware). These platforms
> > > > usually use pmic-glink in order to handle USB-C.
> > > > 
> > > > Or is it micro-USB-OTG port?
> > > > 
> > > 
> > > Yes, it is a USB Type-C port for usb0 and we are using a 3rd party Type-C port
> > > controller for the same. Will be enabling relevant dts node as part of OTG
> > > enablement once driver changes are in place.
> > 
> > Which controller are you using? In the existing designs USB-C works
> > without extra patches for the DWC3 controller.
> > 
> 
> Hi Dmitry,
> 
>  On EVK Platform, the VBUS is controlled by a GPIO from expander. Unlike in
> other platforms like SA8295 ADP, QCS8300 Ride, instead of keeping vbus
> always on for dr_mode as host mode, we wanted to implement vbus control in
> dwc3-qcom.c based on top of [1]. In this patch, there is set_role callback
> present to turn off/on the vbus. So after this patch is merged, we wanted to
> implement vbus control and then flatten DT node and then add vbus supply to
> glue node. Hence made peripheral only dr_mode now.

In such a case VBUS should be controlled by the USB-C controller rather
than DWC3. The reason is pretty simple: the power direction and data
direction are not 1:1 related anymore. The Type-C port manager decides
whether to supply power over USB-C / Vbus or not and (if supported)
which voltage to use. See TCPM's tcpc_dev::set_vbus().

> 
> [1]: https://lore.kernel.org/all/20250812055542.1588528-3-krishna.kurapati@oss.qualcomm.com/
> 
> Regards,
> Krishna,
> 
> > > 
> > > > > 
> > > > > a) dwc3 core callback registration by dwc3 glue driver; this change is under
> > > > >      review in upstream.
> > > > > b) vbus supply enablement for host mode; this change is yet to be submitted
> > > > >      to upstream.
> > > > > 
> > > > > Post the above mentioned driver changes, we are planning to enable OTG on
> > > > > usb0.
> > 
> 

-- 
With best wishes
Dmitry

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