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

[Mathew McBride]

On Sat, May 6, 2023, at 6:47 AM, Rob Herring wrote:
> 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 at traverse.com.au>
> > > 
> > > [1] - https://ten64doc.traverse.com.au/hardware/microcontroller/
> 
> Nothing at that link...

Apologies, we had a DNS issue last week, but it should be OK now.

If you still can't view it, there is the source to the page here:
https://gitlab.com/traversetech/ls1088firmware/ten64-user-manual/-/blob/master/docs/hardware/microcontroller.md

> 
> > > ---
> > >  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.
> 

The firmware implements a fixed set of functions. It's not a general purpose microcontroller intended for arbitrary uses.

The I/O on the microcontroller is wired to various state and control pins on the CPU and power regulators so it's hardware function is fixed in that regard.

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