Re: [PATCH v3 0/3] Add devicetree support of USB for QDU/QRU1000

[Krishna Kurapati PSSNV]

On 5/2/2024 2:39 PM, Dmitry Baryshkov wrote:
> On Thu, 2 May 2024 at 12:04, Komal Bajaj <quic_kbajaj@xxxxxxxxxxx> wrote:
> > This series adds devicetree nodes to support interconnects and usb for qdu/qru1000.
> > This is based on previously sent driver series[1].
> >
> > ------
> > Changes in v3:
> > * As per comments on upstream[2], to get role-switch working on QDU/QRU1000, it was recommended to
> >    use the actual TI switch driver. Since driver doesn't have the functionality to provide role-switch
> >    based on gpio, thus reverting back USB dr_mode to peripheral and removed the remote end-point nodes
> >    and usb-conn-gpio based role switch functionality.
>
> This is not correct. The recommendation was to describe hardware properly.
> Which means adding schema description, adding  ti,your-switch
> compatible to the usb-conn-gpio.c driver, etc.

Hi Dmitry,

 Sorry for the confusion. In the comments [1],

"So the compatible string should be "ti,hd3ss3220". Which is fine to be
used in the platform driver. Just describe the differences in the
schema."

The compatible "ti,hd3ss3220" is already associated with a TI switch 
driver [2]. But it works based on I2C. So we assumed you wanted us to 
make changes to [2] by adding GPIO functionality (which usb-conn-gpio 
exactly does), since the compatible you suggested matched with the TI 
driver.

If it was to add compatible in usb-conn-gpio, then we can support OTG 
functionality with no schema changes I believe, but the compatible 
string might need a different name to avoid clashing with the name in [2].

[1]: 
https://lore.kernel.org/all/CAA8EJppNZrLzT=vGS0NXnKJT_wL+bMB9jFhJ9K7b7FPgFQbcig@xxxxxxxxxxxxxx/

[2]: 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/usb/typec/hd3ss3220.c?h=v6.9-rc2

Regards,
Krishna,

> > * Link to v2: https://lore.kernel.org/linux-arm-msm/20240319091020.15137-1-quic_kbajaj@xxxxxxxxxxx/
> >
> > Changes in v2:
> > * Changes qmpphy node name
> > * Changes dr_mode to otg and added USB-B port USB role switch
> > * Dropped maximum-speed property from usb dwc3 node
> > * Link to v1: https://lore.kernel.org/linux-arm-msm/20240311120859.18489-1-quic_kbajaj@xxxxxxxxxxx/
> >
> > [1] https://lore.kernel.org/linux-arm-msm/20240502082017.13777-1-quic_kbajaj@xxxxxxxxxxx/
> > [2] https://lore.kernel.org/all/CAA8EJppNZrLzT=vGS0NXnKJT_wL+bMB9jFhJ9K7b7FPgFQbcig@xxxxxxxxxxxxxx/
> > ------
> >
> > Komal Bajaj (3):
> >    arm64: dts: qcom: qdu1000: Add USB3 and PHY support
> >    arm64: dts: qcom: qdu1000-idp: enable USB nodes
> >    arm64: dts: qcom: qru1000-idp: enable USB nodes
> >
> >   arch/arm64/boot/dts/qcom/qdu1000-idp.dts |  23 +++++
> >   arch/arm64/boot/dts/qcom/qdu1000.dtsi    | 120 +++++++++++++++++++++++
> >   arch/arm64/boot/dts/qcom/qru1000-idp.dts |  23 +++++
> >   3 files changed, 166 insertions(+)
> >
> > --
> > 2.42.0