Re: [PATCH 1/2] dt-bindings: arm: arm,scmi: add smc/hvc transports

Sudeep Holla
2020-02-07T10:56:54Z

On Thu, Feb 06, 2020 at 02:59:47PM -0700, Rob Herring wrote:
> On Thu, Feb 06, 2020 at 09:01:25PM +0800, peng.fan@nxp.com wrote:
> > From: Peng Fan <peng.fan@nxp.com>
> >
> > SCMI could use SMC/HVC as tranports, so add into devicetree
> > binding doc.
> >
> > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > ---
> > Documentation/devicetree/bindings/arm/arm,scmi.txt | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/arm/arm,scmi.txt b/Documentation/devicetree/bindings/arm/arm,scmi.txt
> > index f493d69e6194..03cff8b55a93 100644
> > --- a/Documentation/devicetree/bindings/arm/arm,scmi.txt
> > +++ b/Documentation/devicetree/bindings/arm/arm,scmi.txt
> > @@ -14,7 +14,7 @@ Required properties:
> >
> > The scmi node with the following properties shall be under the /firmware/ node.
> >
> > -- compatible : shall be "arm,scmi"
> > +- compatible : shall be "arm,scmi" or "arm,scmi-smc"
> > - mboxes: List of phandle and mailbox channel specifiers. It should contain
> > exactly one or two mailboxes, one for transmitting messages("tx")
> > and another optional for receiving the notifications("rx") if
> > @@ -25,6 +25,8 @@ The scmi node with the following properties shall be under the /firmware/ node.
> > protocol identifier for a given sub-node.
> > - #size-cells : should be '0' as 'reg' property doesn't have any size
> > associated with it.
> > +- arm,smc-id : SMC id required when using smc transports
> > +- arm,hvc-id : HVC id required when using hvc transports
>
> Don't the SMC ids get standardized?
>

Unfortunately no. Please don't ask me why ;) as there's no technical reason
to not standardize it. I pushed hard for it, but for this particular case the
SMC/HVC transport is considered to be outside the SCMI protocol standards as
it's transport related.

I completely agree it is total non-sense. I will try to convince them showing
this discussion as reference but can't guarantee anything.

--
Regards,
Sudeep