[PATCH 1/5] dt-bindings: remoteproc: Add PRU consumer bindings

[Rob Herring]

On Tue, Dec 22, 2020 at 8:57 AM Grzegorz Jaszczyk
<grzegorz.jaszczyk at linaro.org> wrote:
>
> Hi Rob,
>
> On Fri, 18 Dec 2020 at 23:51, Rob Herring <robh at kernel.org> wrote:
> >
> > On Wed, Dec 16, 2020 at 9:55 AM Grzegorz Jaszczyk
> > <grzegorz.jaszczyk at linaro.org> wrote:
> > >
> > > Hi Rob,
> > >
> > > On Mon, 14 Dec 2020 at 23:58, Rob Herring <robh at kernel.org> wrote:
> > > >
> > > > On Fri, Dec 11, 2020 at 03:29:29PM +0100, Grzegorz Jaszczyk wrote:
> > > > > From: Suman Anna <s-anna at ti.com>
> > > > >
> > > > > Add a YAML binding document for PRU consumers. The binding includes
> > > > > all the common properties that can be used by different PRU consumer
> > > > > or application nodes and supported by the PRU remoteproc driver.
> > > > > These are used to configure the PRU hardware for specific user
> > > > > applications.
> > > > >
> > > > > The application nodes themselves should define their own bindings.
> > > > >
> > > > > Co-developed-by: Tero Kristo <t-kristo at ti.com>
> > > > > Signed-off-by: Tero Kristo <t-kristo at ti.com>
> > > > > Signed-off-by: Suman Anna <s-anna at ti.com>
> > > > > Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>
> > > > > Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>
> > > > > ---
> > > > >  .../bindings/remoteproc/ti,pru-consumer.yaml  | 64 +++++++++++++++++++
> > > > >  1 file changed, 64 insertions(+)
> > > > >  create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml b/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
> > > > > new file mode 100644
> > > > > index 000000000000..2c5c5e2b6159
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
> > > > > @@ -0,0 +1,64 @@
> > > > > +# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
> > > > > +%YAML 1.2
> > > > > +---
> > > > > +$id: http://devicetree.org/schemas/remoteproc/ti,pru-consumer.yaml#
> > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > > +
> > > > > +title: Common TI PRU Consumer Binding
> > > > > +
> > > > > +maintainers:
> > > > > +  - Suman Anna <s-anna at ti.com>
> > > > > +
> > > > > +description: |
> > > > > +  A PRU application/consumer/user node typically uses one or more PRU device
> > > > > +  nodes to implement a PRU application/functionality. Each application/client
> > > > > +  node would need a reference to at least a PRU node, and optionally define
> > > > > +  some properties needed for hardware/firmware configuration. The below
> > > > > +  properties are a list of common properties supported by the PRU remoteproc
> > > > > +  infrastructure.
> > > > > +
> > > > > +  The application nodes shall define their own bindings like regular platform
> > > > > +  devices, so below are in addition to each node's bindings.
> > > > > +
> > > > > +properties:
> > > > > +  prus:
> > > >
> > > > ti,prus
> > >
> > > Thank you - I will change and post v2 but with this I will run into
> > > issues when this binding will be referenced by some consumer YAML
> > > binding. Running dtbs_check in such case throws:
> > > ... k3-am654-base-board.dt.yaml: serial at 28000: 'ti,prus' does not
> > > match any of the regexes: 'pinctrl-[0-9]+'
> > > In the same time if I will remove this property from that node I am getting:
> > > ... k3-am654-base-board.dt.yaml: serial at 28000: 'ti,prus' is a required property
> > > as expected.
> >
> > Sounds like you didn't update 'ti,prus' in whatever schema you include
> > this one from.
> >
> > >
> > > Getting rid of the comma from this property name workarounds mentioned
> > > problem (which is not proper but allows me to correctly test this
> > > binding): e.g. s/ti,prus/ti-pruss/ or using the previous name without
> > > a comma.
> > > It seems to be an issue with dtbs_check itself which we will encounter
> > > in the future.
> >
> > If not, can you point me to a branch having this problem.
>
> Sure, here is temporary branch with 4 last commits demonstrating
> mentioned issues (when property name contains comma):
> https://git.linaro.org/people/grzegorz.jaszczyk/linux.git/log/?h=ti-pruss-binding-issue
>
> The last commit gets rid of the comma from properties names which
> successfully w/a the problem.
>
> Please note that those are only TEMP commits which demonstrates the
> mentioned issue. I've put error logs with some notes in commit log to
> ease understanding what issues are seen when.

The problem is any property with a vendor prefix has to define a type.
There's not a way to define a 'common vendor property' and distinguish
both cases in the meta-schemas. I'd like to come up with a more robust
mechanism where we just detect if a property has a defined type or
not. It should be possible to extract that. (Related, I also want to
check for conflicting types.)

How many cases of 'ti,prus' do you expect to have and what's the range
of number of phandles? Either you should just not have the common
schema and just define the properties in each consumer or don't put
additional constraints into the consumer schemas (i.e omit the
properties in 'properties' and use 'unevaluatedProperties').

Also, I think you can get rid of 'ti,pruss-gp-mux-sel'. Can't it just
be an arg cell in 'ti,prus' entries?

Rob