On 15/03/18 13:46, Robin Murphy wrote: > On 12/03/18 10:41, Roger Quadros wrote: > [...] >>>>> @@ -0,0 +1,75 @@ >>>>> +USB Connector >>>>> +============= >>>>> + >>>>> +USB connector node represents physical USB connector. It should be >>>>> +a child of USB interface controller. >>>>> + >>>>> +Required properties: >>>>> +- compatible: describes type of the connector, must be one of: >>>>> + "usb-a-connector", >>>>> + "usb-b-connector", >>>>> + "usb-c-connector". >>>> compatible should be just "usb-connector" >>>> >>>> Type should be a property >>>> >>>> type: type of usb connector "A", "B", "AB", "C" >>>> AB is for dual-role connectors. >>> >>> I have proposed such property (and size also) in my first RFC [1]. Rod >>> did not like it :) >>> >>> [1]: https://marc.info/?l=devicetree&m=150660411515233&w=2 >>> >> >> This is what Rob says here https://patchwork.kernel.org/patch/9976043/ >> "We did "type" for hdmi-connector, but I think I'd really prefer >> compatible be used to distinguish as least where it may matter to s/w. >> In the HDMI case, they all are pretty much the same, just different >> physical size." >> >> So the question is. Does it matter to this particular software implementation >> if it is type A,B,C connector? >> If yes, how? >> >> Type A will never have any alternate function. It is always dedicated to USB. > > In USB spec terms, at least. In reality there are things like the cool trick > Rockchip SoCs do whereby they can expose the debug UART Rx/Tx through the OTG > port's D+/D- pins, and that is on a type A connector in many products. I'm > guessing that's probably beyond the scope of this binding, though. > >> Also does the size "full", "micro", "mini" matter to software? > > If it means the user can look in sysfs to easily correlate logical ports with > physical connectors that's certainly handy (e.g. on something like Odroid-XU > where the two USB3 ports are brought out to an A and a micro-AB connector > respectively).
But this logic fails if both connectors are the same type/size. This is where the label comes in handy. The labels can be unique and end user can identify the port using that. > > Robin. -- cheers, -roger Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
