Deprecate 'sub-node:' and add a more general 'child-binding:' mechanism
to bindings. Keep supporting 'sub-node:', but print a deprecation
warning when it's used.
Like 'sub-node:', 'child-binding:' gives a binding to child nodes, but
the binding is required to be a complete binding, and is treated (and
checked) like a normal binding.
'child-binding:' can in turn contain another 'child-binding:', up to any
number of levels. This is automatic from treating it like a normal
binding, and from the code initializing parent Devices before child
Devices.
This lets nodes give bindings to grandchildren.
For example, take this devicetree fragment:
parent {
compatible = "foo";
child-1 {
grandchild-1 {
...
};
grandchild-2 {
...
};
};
child-2 {
grandchild-3 {
...
};
};
};
The binding for 'foo' could provide bindings for grandchild-1/2/3 like
this:
compatible: "foo"
# Binding for children
child-binding:
title: ...
description: ...
...
# Binding for grandchildren
child-binding:
title: ...
description: ...
properties:
...
Due to implementation issues with the old devicetree scripts, only two
levels of 'child-binding:' is supported for now. This limitation will go
away in Zephyr 2.2.
Piggyback shortening 'description:' and 'title:' in some bindings that
provide child bindings. This makes the generated header a bit neater.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
0b1ab4ab09