The current DT binding documentation is not ideal as it is just free form
text with at most only a loose structure. This makes reviewing bindings a
manual process. The bindings are often duplicating information that's
already defined elsewhere and missing information one would need to
validate a DTS file. The examples in binding documents are not built and
a source of lots of typos sometimes found in review and sometimes not.
Secondly, there's no verification that DTS files match what the
documentation says. While dtc does do some checking (and has gained more
recently), it can't do per binding checks as it would have to understand
thousands of compatible strings to match on.
There's been a number of proposals over the years to address validation.
They've all suffered from inventing their own validation language and the
effort it would take to fully define and flush out a validation language.
Enter json-schema. The language has a defined specification, maps well to
DT data, and there are numerous existing tools which can be leveraged.
The actual DT schema doc files are stored as YAML using only a JSON
compatible subset. YAML is considered more human readable allowing
comments for example.
This series adds the build support, some documentation, and converts
some bindings (mostly ARM board/soc bindings). The tools, core schema,
and meta-schema are in a separate repository[1]. This might eventually
be integrated with dtc or added to the kernel, but for now I plan to
keep it separate.
Future plans/ideas:
- Validate examples against the schema. Currently, they are just built
with dtc.
- Support single targets in addition to validating all enabled dtb
targets.
- Better control of which schemas to use for validation such as core
only or specific lists of schemas. This will make for more easily
testing new schema and filtering warnings.
- Printing out nodes without any specific schema (i.e. missing schema).
This series is dependent on the dt/next branch and is available here[2].
The branch also has a doc2yaml script which can help convert binding
files. It's not perfect, but works pretty well considering the input is
free form text.
Rob
[1] https://github.com/robherring/yaml-bindings
[2] git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git yaml-bindings
Rob Herring (36):
dt-bindings: arm: alpine: Move CPU control related binding to
cpu-enable-method/al,alpine-smp
dt-bindings: arm: amlogic: Move 'amlogic,meson-gx-ao-secure' binding
to its own file
dt-bindings: arm: atmel: Move various sys registers out of SoC binding
doc
dt-bindings: arm: fsl: Move DCFG and SCFG bindings to their own docs
dt-bindings: arm: renesas: Move 'renesas,prr' binding to its own doc
dt-bindings: arm: zte: Move sysctrl bindings to their own doc
kbuild: Add support for DT binding schema checks
dt-bindings: Add a writing DT schemas how-to and annotated example
dt-bindings: Convert trivial-devices.txt to json-schema
dt-bindings: altera: Convert clkmgr binding to json-schema
dt-bindings: timer: Convert ARM timer bindings to json-schema
dt-bindings: arm: Convert cpu binding to json-schema
dt-bindings: arm: Convert PMU binding to json-schema
dt-bindings: arm: Convert primecell binding to json-schema
dt-bindings: arm: Convert Actions Semi bindings to jsonschema
dt-bindings: arm: Convert Alpine board/soc bindings to json-schema
dt-bindings: arm: Convert Altera board/soc bindings to json-schema
dt-bindings: arm: Convert Amlogic board/soc bindings to json-schema
dt-bindings: arm: Convert Atmel board/soc bindings to json-schema
dt-bindings: arm: Convert Calxeda board/soc bindings to json-schema
dt-bindings: arm: Convert TI davinci board/soc bindings to json-schema
dt-bindings: arm: Convert FSL board/soc bindings to json-schema
dt-bindings: arm: Convert MediaTek board/soc bindings to json-schema
dt-bindings: arm: Convert TI nspire board/soc bindings to json-schema
dt-bindings: arm: Convert Oxford Semi board/soc bindings to
json-schema
dt-bindings: arm: Convert QCom board/soc bindings to json-schema
dt-bindings: arm: Convert Realtek board/soc bindings to json-schema
dt-bindings: arm: Convert Rockchip board/soc bindings to json-schema
dt-bindings: arm: Convert Renesas board/soc bindings to json-schema
dt-bindings: arm: Convert CSR SiRF board/soc bindings to json-schema
dt-bindings: arm: Convert SPEAr board/soc bindings to json-schema
dt-bindings: arm: Convert ST STi board/soc bindings to json-schema
dt-bindings: arm: Convert Tegra board/soc bindings to json-schema
dt-bindings: arm: Convert VIA board/soc bindings to json-schema
dt-bindings: arm: Convert Xilinx board/soc bindings to json-schema
dt-bindings: arm: Convert ZTE board/soc bindings to json-schema
.gitignore| 1 +
Documentation/Makefile| 2 +-
Documentation/devicetree/bindings/.gitignore | 2 +
