Re: [PATCH v2 1/4] dt-bindings: usb: dwc3-xilinx: Add MMI USB support on Versal Gen2 platform

[Krzysztof Kozlowski <krzk@kernel.org>]

On 31/03/2026 11:18, Pandey, Radhey Shyam wrote:
>> On Tue, Mar 31, 2026 at 12:33:01AM +0530, Radhey Shyam Pandey wrote:
>>> Versal Gen2 platform multimedia integrated (MMI) module has a USB3.2 Gen
>>> 2x1 Dual Role Device IP. Introduce a new compatibility string to support
>>> it. The USB wrapper registers reside in the MMI UDH system-level control
>>> registers (SLCR) block, so instead of a dedicated reg property, add
>>> xlnx,usb-syscon phandle with four cells specifying register offsets for
>>> USB2 PHY, USB3 PHY, USB DRD, and USB power configuration within the SLCR.
>>>
>>> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
>>> ---
>>> Changes for v2:
>>> - Add blank line after compatible as suggested by Krzysztof.
>>> - Retain the mmi suffix in the compatible string, as this USB 3.2 Gen2
>>>    IP from Synopsys is part of the dedicated Multimedia Interface. The
>>>    Versal Gen2 platform also includes a separate USB 2.0 controller,
>>>    and the mmi suffix uniquely distinguishes between the two USB
>>>    controllers. MMI is an independent subsystem particularly targeted for
>>>    deployment in Multi-Media related applications. The MMI block include
>>>    following submodules: UDH: USB3.2 Gen 2x1 Dual Role Device, DisplayPort
>>>    Transmit Controller, Security Module (ESM) for DisplayPort and HDMI
>>>    Controllers, DP AUX-I2C PHY.
>>> - For MMI USB define parent address space i.e UDH block.
>>> - Fix inconsistent MHz spacing to use SI convention with spaces.
>>> - Move description before $ref and items in xlnx,usb-syscon property.
>>> - Restore original zynqmp-dwc3 example, add new versal2-mmi-dwc3 example.
>>> - Use 'usb' node name (without unit address) for versal2 example since
>>>    it has no reg property.
>>> - Use 1/1 address/size configuration in versal2 example, use lowercase
>>>    hex in syscon offsets.
>>> ---
>>>   .../devicetree/bindings/usb/dwc3-xilinx.yaml  | 70 ++++++++++++++++++-
>>>   1 file changed, 67 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml b/Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml
>>> index d6823ef5f9a7..5e31b961aff7 100644
>>> --- a/Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml
>>> +++ b/Documentation/devicetree/bindings/usb/dwc3-xilinx.yaml
>>> @@ -15,6 +15,8 @@ properties:
>>>         - enum:
>>>             - xlnx,zynqmp-dwc3
>>>             - xlnx,versal-dwc3
>>> +          - xlnx,versal2-mmi-dwc3
>> I am not going to ask the same questions.
> 
> I have provided the explanation in v2 changelog.
> Retain the mmi suffix in the compatible string, as this USB 3.2 Gen2
> IP from Synopsys is part of the dedicated Multimedia Interface. The
> Versal Gen2 platform also includes a separate USB 2.0 controller,
> and the mmi suffix uniquely distinguishes between the two USB
> controllers.
> 
> Let me know if you still have reservation in this approach (using
> <vendor>,<soc>-<subsystem>-<ip>). Or any other alternative
> based on IP version etc please suggest.

Commit msg must explain that you have two different devices. And then
explain what is the difference between versal2-dwc3 and versal2-mmi-dwc3.

Best regards,
Krzysztof