Re: [PATCH 1/2] dt-bindings: usb/ti,am62-usb.yaml: Add ti,lane-reverse property

[Krzysztof Kozlowski <krzk@kernel.org>]

On 19/09/2025 00:41, Richard GENOUD wrote:
> Hi Krzysztof,
> Le 14/09/2025 à 16:55, Krzysztof Kozlowski a écrit :
>> On 09/09/2025 11:11, Richard GENOUD wrote:
>>>>> diff --git a/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml b/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml
>>>>> index f6e6d084d1c5..ba894d610af0 100644
>>>>> --- a/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml
>>>>> +++ b/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml
>>>>> @@ -36,6 +36,11 @@ properties:
>>>>>        items:
>>>>>          - const: ref
>>>>>    
>>>>> +  ti,lane-reverse:
>>>>> +    description:
>>>>> +      Should be present if D+ and D- lanes have to be swapped.
>>>>> +    type: boolean
>>>>
>>>> What is not working with existing data-lanes property?
>>> Hum, indeed. data-lanes could definitely be used here.
>>>
>>>>
>>>> Plus, lanes are swapped per port, not for entire device, no?
>>> I'm not sure to get what you mean here.
>>> The use case I'm trying to address is:
>>> pin AD10(USB1_DM) of the AM625 is routed to USB_DP pin of an USB connector.
>>> And pin AE9(USB1_DP) of the AM625 is routed to USB_DM pin of an USB
>>
>> I understand what you are trying to achieve and my comment was exactly
>> about it. You want to change properties of specific connection, high
>> speed in that case, right? So this belongs to specific port. Just do the
>> homework and run `git grep data-lanes`.
> I'm ok with data-lanes, I'm not arguing on that part.
> 
> I'm being confused by using it on the port, it doesn't seem to fit the 
> hardware.

Why? You do have ports in your hardware, right? Physical connections/wires?

> Let me show the example with the dts k3-am62-main.dtsi:

That's DTS, not exactly hardware.

> 	usbss0: dwc3-usb@f900000 {
> 		compatible = "ti,am62-usb";
> 		reg = <0x00 0x0f900000 0x00 0x800>,
> 		      <0x00 0x0f908000 0x00 0x400>;
> 		clocks = <&k3_clks 161 3>;
> 		clock-names = "ref";
> 		ti,syscon-phy-pll-refclk = <&usb0_phy_ctrl 0x0>;
> 		#address-cells = <2>;
> 		#size-cells = <2>;
> 		power-domains = <&k3_pds 178 TI_SCI_PD_EXCLUSIVE>;
> 		ranges;
> 		status = "disabled";
> 
> 		usb0: usb@31000000 {
> 			compatible = "snps,dwc3";
> 			reg = <0x00 0x31000000 0x00 0x50000>;
> 			interrupts = <GIC_SPI 188 IRQ_TYPE_LEVEL_HIGH>,
> 				     <GIC_SPI 188 IRQ_TYPE_LEVEL_HIGH>;
> 			interrupt-names = "host", "peripheral";
> 			maximum-speed = "high-speed";
> 			dr_mode = "otg";
> 			snps,usb2-gadget-lpm-disable;
> 			snps,usb2-lpm-disable;
> 		};
> 	};

And where is your proper OF graph?

> The bit used to swap data lanes is in MMR_USB2SS_CFG_PHY_CONFIG Register 
> at address 0x0F900008, so it should be in usbss0 node to match the 
> hardware right?
> 
> (I've checked on all ti,am62-usb devices, they have only one port)

So I don't get what is not matching hardware...



Best regards,
Krzysztof