Re: [PATCH V2 PROOF OF CONCEPT 2/1] trigger: ledtrig-usbport: read initial state from DT

From: RafaÅ MiÅecki
Date: Wed Jul 13 2016 - 11:06:52 EST


On 13 July 2016 at 16:48, Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx> wrote:
> On 07/13/2016 02:42 PM, RafaÅ MiÅecki wrote:
>>
>> This allows specifying USB ports that should be observed by a trigger
>> right after activating it. Example:
>>
>> usb {
>> gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
>> linux,default-trigger = "usbport";
>> usb-controllers = <&ohci>, <&ehci>, <&xhci USB_HCD_SHARED>;
>> usb-ports = "1", "1", "1";
>
>
> Port is a numerical value, right?
> Wouldn't it be better to define it as an array of integers?
>
> e.g.: usb-ports = <1>. <1>, <1>;

Not always. Let me quote this part of "usbport" documentation:

> This also allows handling devices with internal hubs (when root hub's port has
> always a device (hub) connected). User can simply specify specify internal hub
> ports then (e.g. 1-1.1, 1-1.2, etc.).

In such case we'd need usb-ports = "1.1", "1.2";

Anyway, there is a discussion ongoing in:
[PATCH V2 0/1] usb: add HCD providers
so let's see if someone will have a better idea for referencing USB
ports inside DT.