Kernel-4.18.0-80.el8_submitting-patches

Submitting devicetree (DT) binding patches

I. For patch submitters

0. Normal patch submission rules from Documentation/process/submitting-patches.rst
   applies.

1. The Documentation/ and include/dt-bindings/ portion of the patch should
   be a separate patch. The preferred subject prefix for binding patches is:

   “dt-bindings: : …”

   The 80 characters of the subject are precious. It is recommended to not
   use “Documentation” or “doc” because that is implied. All bindings are
   docs. Repeating “binding” again should also be avoided.

2. Submit the entire series to the devicetree mailinglist at

   devicetree@vger.kernel.org

   and Cc: the DT maintainers. Use scripts/get_maintainer.pl to identify
   all of the DT maintainers.

3. The Documentation/ portion of the patch should come in the series before
   the code implementing the binding.

4. Any compatible strings used in a chip or board DTS file must be
   previously documented in the corresponding DT binding text file
   in Documentation/devicetree/bindings. This rule applies even if
   the Linux device driver does not yet match on the compatible
   string. [ checkpatch will emit warnings if this step is not
   followed as of commit bff5da4335256513497cc8c79f9a9d1665e09864
   (“checkpatch: add DT compatible string documentation checks”). ]

5. The wildcard ““ may be used in compatible strings, as in
   the following example:

   - compatible: Must contain '"nvidia,<chip>-pcie",
     "nvidia,tegra20-pcie"' where <chip> is tegra30, tegra132, ...
   

   As in the above example, the known values of ““ should be
   documented if it is used.

6. If a documented compatible string is not yet matched by the
   driver, the documentation should also include a compatible
   string that is matched by the driver (as in the “nvidia,tegra20-pcie”
   example above).

II. For kernel maintainers

1. If you aren’t comfortable reviewing a given binding, reply to it and ask
   the devicetree maintainers for guidance. This will help them prioritize
   which ones to review and which ones are ok to let go.

2. For driver (not subsystem) bindings: If you are comfortable with the
   binding, and it hasn’t received an Acked-by from the devicetree
   maintainers after a few weeks, go ahead and take it.

   Subsystem bindings (anything affecting more than a single device)
   then getting a devicetree maintainer to review it is required.

3. For a series going though multiple trees, the binding patch should be
   kept with the driver using the binding.

III. Notes

0. Please see …bindings/ABI.txt for details regarding devicetree ABI.

1. This document is intended as a general familiarization with the process as
   decided at the 2013 Kernel Summit. When in doubt, the current word of the
   devicetree maintainers overrules this document. In that situation, a patch
   updating this document would be appreciated.