Re: [PATCH 2/3] usb: add DT bindings for farady fotg2 host controller

[Rob Herring]

On Fri, Feb 17, 2017 at 4:07 AM, Hans Ulli Kroll
<ulli.kroll@xxxxxxxxxxxxxx> wrote:
> Hi Rob,
>
> On Wed, 15 Feb 2017, Rob Herring wrote:
>
>> On Wed, Feb 08, 2017 at 09:00:09PM +0100, Hans Ulli Kroll wrote:
>> > This adds DT bindings for the Faraday FOTG2 host controller.
>> >
>> > Signed-off-by: Hans Ulli Kroll <ulli.kroll@xxxxxxxxxxxxxx>
>> > ---
>> >  Documentation/devicetree/bindings/usb/fotg2-host.txt | 15 +++++++++++++++
>> >  1 file changed, 15 insertions(+)
>> >  create mode 100644 Documentation/devicetree/bindings/usb/fotg2-host.txt
>> >
>> > diff --git a/Documentation/devicetree/bindings/usb/fotg2-host.txt b/Documentation/devicetree/bindings/usb/fotg2-host.txt
>> > new file mode 100644
>> > index 000000000000..4c07566a4bf5
>> > --- /dev/null
>> > +++ b/Documentation/devicetree/bindings/usb/fotg2-host.txt
>> > @@ -0,0 +1,15 @@
>> > +Faraday FOTG Host controller
>> > +
>> > +Required properties:
>> > +
>> > +- compatible: should be "faraday,fotg210-hcd"
>>
>> hcd as in "host controller driver"? Bindings describe h/w not drivers.
>>
>> It's an OTG controller or host controller?
>>
>
> here only the host controller part used.
>
> faraday fotg2 is a dual role hcd/otg device and here is only the
> host part used.

Because you don't care about device mode or restricted by the IP
configuration or SoC integration? The former is a user choice and
shouldn't be part of DT. The latter should be implied by an SoC
specific compatible string. Using only a compatible string for a
licensed IP is not specific enough as vendors use differing versions
and integrate them in different ways.

Rob