[PATCH V5 1/6] dt-bindings: usb: Add NVIDIA Tegra234 XUSB host controller binding

[Jon Hunter]

On 08/01/2023 15:21, Krzysztof Kozlowski wrote:

...

> On 06/01/2023 16:28, Jon Hunter wrote:
>> +  phys:
>> +    minItems: 1
>> +    maxItems: 8
>> +
>> +  phy-names:
>> +    minItems: 1
>> +    maxItems: 8
>> +    items:
>> +      enum:
>> +        - usb2-0
>> +        - usb2-1
>> +        - usb2-2
>> +        - usb2-3
>> +        - usb3-0
>> +        - usb3-1
>> +        - usb3-2
>> +        - usb3-3
> 
> Why do you have so many optional phys? In what case you would put there
> usb2-0 and usb3-3 together? Or even 8 phys at the same time? IOW, what
> are the differences between them and why one controller would be
> connected once to usb3-2 and once to usb3-3 phy? And once to both?


Here is the description from the device documentation ...

"The NVIDIA Orin series System-on-Chip (SoC) has one xHCI host 
controller and one USB 3.2 Gen1 x1 device controller. The two 
controllers control a total of up to eight exposed ports. There are up 
to four USB 2.0 ports and up to four USB 3.2 Gen1 x1 ports."

So there are eight phys and we could have 4 USB2 and 4 USB3. Depending 
on which pins you want to use, you could have various combinations. I 
can add these details to the binding doc if that helps.	

Thanks
Jon

-- 
nvpublic