Most bindings look something like this:
title: Foo
description: This binding provides a base representation of Foo
That kind of description doesn't add any useful information, as it's
just the title along with some copy-pasted text. I'm not sure what "base
representation" was supposed to mean originally either.
Many bindings also put something that's closer to a description in the
title, because it's not clear what's expected or how the title is used.
In reality, the title isn't used anywhere. 'description:' on the other
hand shows up as a comment in the generated header.
Deprecate 'title:' and generate a long informative warning if it shows
up in a binding.
Next commits will clean up the 'description:' strings (bringing them
closer to 'title:' in most cases) and remove 'title:' from all bindings.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Implement a nice generalization suggested by Bobby Noelte.
Instead of having a generic #cells key in bindings, have source-specific
*-cells keys. Some examples:
interrupt-cells:
- irq
- priority
- flags
gpio-cells:
- pin
- flags
pwm-cells:
- channel
- period
This makes bindings a bit easier to read, and allows a node to be a
controller for many different 'phandle-array' properties.
The prefix before *-cells is derived from the property name, meaning
there's no fixed set of *-cells keys. This is possible because of the
earlier 'phandle-array' generalization.
The older #cells key is supported for backwards compatibility, but
generates a deprecation warning.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Generating generic information for 'type: phandle-array' properties in
edtlib was difficult due to defining phandle-array as just a list of
phandles and numbers. To make sense of a phandle-array property like
'pwms', you have to know that #pwm-cells is expected to appear on
each referenced controller, and that the binding for the controller has
a #cells.
Because of this, handling of various 'type: phandle-array' properties
was previously hardcoded in edtlib and exposed through properties like
Node.pwms, instead of through the generic Node.props (though with a lot
of shared code).
In practice, it turns out that all 'type: phandle-array' properties in
Zephyr work exactly the same way: They all have names that end in -s,
the 's' is removed to derive the name of related properties, and they
all look up #cells in the binding for the controller, which gives names
to the data values.
Strengthen the definition of 'type: phandle-array' to mean a property
that works exactly like the existing phandle-array properties (which
also means requiring that the name ends in -s). This removes a ton of
hardcoding from edtlib and allows new 'type: phandle-array' properties
to be added without making any code changes.
If we ever need a property type that's a list of phandles and numbers
but that doesn't follow this scheme, then we could add a separate type
for it. We should check if the standard scheme is fine first though.
The only property type for which no information is generated is now
'compound'.
There's some inconsistency in how we generate identifiers for clocks
compared to other 'type: phandle-array' properties, so keep
special-casing them for now in gen_defines.py (see the comment in
write_clocks()).
This change also enabled a bunch of other simplifications, like reusing
the ControllerAndData class for interrupts.
Piggyback generalization of *-map properties so that they work for any
phandle-array properties. It's now possible to have things like
'io-channel-map', if you need to.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Ulf Magnusson