Re: [PATCH 1/4] dt-bindings: trivial-devices: add traverse,ten64-controller

[Rob Herring <robh@kernel.org>]

On Tue, May 02, 2023 at 10:02:27AM +0200, Krzysztof Kozlowski wrote:
> On 01/05/2023 08:47, Mathew McBride wrote:
> > Add the Ten64 family board controller[1] to the trivial devices list.
> > 
> > Signed-off-by: Mathew McBride <matt@traverse.com.au>
> > 
> > [1] - https://ten64doc.traverse.com.au/hardware/microcontroller/

Nothing at that link...

> > ---
> >  Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
> > index 246863a9bc7e..638e16fc9f71 100644
> > --- a/Documentation/devicetree/bindings/trivial-devices.yaml
> > +++ b/Documentation/devicetree/bindings/trivial-devices.yaml
> > @@ -397,6 +397,8 @@ properties:
> >            - ti,tps544b25
> >            - ti,tps544c20
> >            - ti,tps544c25
> > +            # Board controller for Ten64 family mainboards
> > +          - traverse,ten64-controller
> 
> This is not a ten64 device, but just component of the SoC, right?
> Regular NXP LPC804 Cortex-M0 which you just program with different firmware.
> 
> Basically this means you describe the firmware in Devicetree...
> 
> Rob,
> 
> What are the guidelines for generic co-processors (some Cortex-M)
> exposing just I2C line and nothing more? Do we want to describe the
> actual firmware running there?

It really depends if the firmware implements a fixed function or varies 
frequently. If there's resources exposed in DT dependent on the 
firmware, then the binding kind of has to be a binding for the firmware.

DT is the view of hardware as presented to the OS whether the h/w is 
implemented in gates or firmware.

Rob