checkpatch: add DT compatible string documentation checks

This adds a simple check that any compatible strings in DeviceTree dts
files are present in Documentation/devicetree/bindings.  Vendor prefixes
are also checked for existing in vendor-prefixes.txt These should be
temporary checks until we have more sophisticated binding schema
checking.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d89e4299c19d..05c99c0b7e6c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2040,6 +2040,33 @@ sub process {
                              "Use of $flag is deprecated, please use \`$replacement->{$flag} instead.\n" . $herecurr) if ($replacement->{$flag});
                 }
 
+# check for DT compatible documentation
+                if (defined $root && $realfile =~ /\.dts/ &&
+                    $rawline =~ /^\+\s*compatible\s*=/) {
+                        my @compats = $rawline =~ /\"([a-zA-Z0-9\-\,\.\+_]+)\"/g;
+
+                        foreach my $compat (@compats) {
+                                my $compat2 = $compat;
+                                my $dt_path =  $root . "/Documentation/devicetree/bindings/";
+                                $compat2 =~ s/\,[a-z]*\-/\,<\.\*>\-/;
+                                `grep -Erq "$compat|$compat2" $dt_path`;
+                                if ( $? >> 8 ) {
+                                        WARN("UNDOCUMENTED_DT_STRING",
+                                             "DT compatible string \"$compat\" appears un-documented -- check $dt_path\n" . $herecurr);
+                                }
+
+                                my $vendor = $compat;
+                                my $vendor_path = $dt_path . "vendor-prefixes.txt";
+                                next if (! -f $vendor_path);
+                                $vendor =~ s/^([a-zA-Z0-9]+)\,.*/$1/;
+                                `grep -Eq "$vendor" $vendor_path`;
+                                if ( $? >> 8 ) {
+                                        WARN("UNDOCUMENTED_DT_STRING",
+                                             "DT compatible string vendor \"$vendor\" appears un-documented -- check $vendor_path\n" . $herecurr);
+                                }
+                        }
+                }
+
 # check we are in a valid source file if not then ignore this hunk
                 next if ($realfile !~ /\.(h|c|s|S|pl|sh)$/);