Add binding support for a 'path' property type, for properties that are
assigned node paths. Usually, paths are assigned with path references
like 'foo = &label' (common in /chosen), but plain strings are accepted
as well as long as they're valid paths.
The 'path' type is mostly for completeness at this point, but might be
useful for https://github.com/zephyrproject-rtos/zephyr/issues/21623.
The support is there already in dtlib.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
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>
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>
Instead of
properties:
compatible:
constraint: "foo"
, just have
compatible: "foo"
at the top level of the binding.
For backwards compatibility, the old 'properties: compatible: ...' form
is still accepted for now, and is treated the same as a single-element
'compatible:'.
The old syntax was inspired by dt-schema (though it isn't
dt-schema-compatible), which is in turn a thin wrapper around
json-schema (the idea is to transform .dts files into YAML and then
verify them).
Maybe the idea was to gradually switch the syntax over to dt-schema and
then be able to use unmodified dt-schema bindings, but dt-schema is
really a different kind of tool (a completely standalone linter), and
works very differently from our stuff (see schemas/dt-core.yaml in the
dt-schema repo to get an idea of just how differently).
Better to keep it simple.
This commit also piggybacks some clarifications to the binding template
re. '#cells:'.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Add two new type-checked property types 'phandles' and 'phandle-array'
to edtlib.
'phandles' is for pure lists of phandles, with no other data, like
foo = < &bar &baz ... >
'phandle-array' is for lists of phandles and (possibly) numbers, like
foo = < &bar 1 2 &baz 3 4 ... >
dt-schema also has the 'phandle-array' type.
Property.val (in edtlib) is set to an array of Device objects for the
'phandles' type.
For the 'phandle-array' type, no Property object is created. This type
is only used for type checking.
Also refactor how types that do not create a Property object
('phandle-array' and 'compound') are handled. Have _prop_val() return
None for them.
The new types are implemented with two new TYPE_PHANDLES and
TYPE_PHANDLES_AND_NUMS types at the dtlib level. There is also a new
Property.to_nodes() functions for fetching the Nodes for an array of
phandles, with type checking.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Add a 'const' property to bindings for any properties that are expected
to have a specifi known value. For example, #address-cells for an I2C
bus should always be '1'. So we can do something like the following in
the I2C bus binding:
"#address-cells":
type: int
category: required
const: 1
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Property type-checking has been pretty rudimentary until now, only
checking things like the length being divisible by 4 for 'type: array',
and strings being null-terminated. In particular, no checking was done
for 'type: uint8-array', letting
jedec-id = < 0xc8 0x28 0x17 >;
slip through when
jedec-id = [ 0xc8 0x28 0x17 ];
was intended.
Fix it by adding a syntax-based type checker:
1. Add Property.type, which gives a high-level type for the property,
derived from the markers added in the previous commit.
This includes types like TYPE_EMPTY ('foo;'),
TYPE_NUM ('foo = < 3 >;'), TYPE_BYTES ('foo = [ 01 02 ];'),
TYPE_STRINGS ('foo = "bar", "baz"'),
TYPE_PHANDLE ('foo = < &bar >;'), and TYPE_COMPOUND (everything not
recognized).
See the Property.type docstring in dtlib for more info.
2. Use the high-level type in
Property.to_num()/to_string()/to_node()/etc. to verify that the
property was assigned in an expected way for the type.
If the assignment looks bad, give a helpful error:
expected property 'nums' on /foo/bar in some.dts to be assigned
with 'nums = < (number) (number) ... >', not 'nums = "oops";'
Some other related changes are included as well:
- There's a new Property.to_bytes() function that works like accessing
Property.bytes, except with an added check for the value being
assigned like 'foo = [ ... ]'.
This function solves problems like the jedec-id one.
- There's a new Property.to_path() function for fetching the
referenced node for assignments like 'foo = &node;', with type
checking. (Strings are accepted too, as long as they give the path
to an existing node.)
This function is used for /chosen and /aliases.
- A new 'type: phandle' type can now be given in bindings, for
properties that are assigned like 'foo = < &node >;'.
- Property.__str__() now displays phandles and path references as they
were written (e.g. '< &foo >' instead of '< 0x1 >', if the
allocated phandle happened to be 1).
- Property.to_num() and Property.to_nums() no longer take a 'length'
parameter, because it makes no sense with the type checking.
- The global dtlib.to_string() and dtlib.to_strings() functions were
removed, because they're not that useful.
- More tests were added, along with misc. minor cleanup in various
places.
- Probably other stuff I forgot.
The more strict type checking in dtlib indirectly makes some parts of
edtlib more strict as well (wherever Property.to_*() is used).
Fixes: #18131
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Add a new DTS/binding parser to scripts/dts/ for generating
generated_dts_board.conf and generated_dts_board_unfixed.h.
The old code is kept to generate some deprecated defines, using the
--deprecated-only flag. It will be removed later.
The new parser is implemented in three files in scripts/dts/:
dtlib.py:
A low-level .dts parsing library. This is similar to devicetree.py in
the old code, but is a general robust DTS parser that doesn't rely on
preprocessing.
edtlib.py (e for extended):
A library built on top of dtlib.py that brings together data from DTS
files and bindings and creates Device instances with all the data for
a device.
gen_defines.py:
A script that uses edtlib.py to generate generated_dts_board.conf and
generated_dts_board_unfixed.h. Corresponds to extract_dts_includes.py
and the files in extract/ in the old code.
testdtlib.py:
Test suite for dtlib.py. Can be run directly as a script.
testedtlib.py (uses test.dts and test-bindings/):
Test suite for edtlib.py. Can be run directly as a script.
The test suites will be run automatically in CI.
The new code turns some things that were warnings (or not checked) in
the old code into errors, like missing properties that are specified
with 'category: required' in the binding for the node.
The code includes lots of documentation and tries to give helpful error
messages instead of Python errors.
Co-authored-by: Kumar Gala <kumar.gala@linaro.org>
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Ulf Magnusson