kbuild: Add support for DT binding schema checks

This adds the build infrastructure for checking DT binding schema
documents and validating dts files using the binding schema.

Check DT binding schema documents:
make dt_binding_check

Build dts files and check using DT binding schema:
make dtbs_check

Optionally, DT_SCHEMA_FILES can be passed in with a schema file(s) to
use for validation. This makes it easier to find and fix errors
generated by a specific schema.

Currently, the validation targets are separate from a normal build to
avoid a hard dependency on the external DT schema project and because
there are lots of warnings generated.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-doc@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

1 files changed, 10 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index 2f36db897895..a3e2db2a3119 100644
--- a/Makefile
+++ b/Makefile
@@ -1232,10 +1232,13 @@ ifneq ($(dtstree),)
 %.dtb: prepare3 scripts_dtc
         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
 
-PHONY += dtbs dtbs_install
-dtbs: prepare3 scripts_dtc
+PHONY += dtbs dtbs_install dt_binding_check
+dtbs dtbs_check: prepare3 scripts_dtc
         $(Q)$(MAKE) $(build)=$(dtstree)
 
+dtbs_check: export CHECK_DTBS=1
+dtbs_check: dt_binding_check
+
 dtbs_install:
         $(Q)$(MAKE) $(dtbinst)=$(dtstree)
 
@@ -1249,6 +1252,9 @@ PHONY += scripts_dtc
 scripts_dtc: scripts_basic
         $(Q)$(MAKE) $(build)=scripts/dtc
 
+dt_binding_check: scripts_dtc
+        $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
+
 # ---------------------------------------------------------------------------
 # Modules
 
@@ -1611,7 +1617,8 @@ clean: $(clean-dirs)
         $(call cmd,rmfiles)
         @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
                 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
-                -o -name '*.ko.*' -o -name '*.dtb' -o -name '*.dtb.S' \
+                -o -name '*.ko.*' \
+                -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
                 -o -name '*.dwo' -o -name '*.lst' \
                 -o -name '*.su'  \
                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \