1 files changed, 23 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/submitting-patches.txt b/Documentation/devicetree/bindings/submitting-patches.txt
index b7ba01ad1426..56742bc70218 100644
--- a/Documentation/devicetree/bindings/submitting-patches.txt
+++ b/Documentation/devicetree/bindings/submitting-patches.txt
@@ -15,6 +15,29 @@ I. For patch submitters
   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 "<chip>" 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 "<chip>" 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