[PATCH] dt-bindings: Add a minimum version check for dtschema

[Rob Herring]

The dtschema package must be somewhat up to date as the tools and
meta-schema checks are still evolving. Implement a version check,
so this can be enforced. This will help ensure new schema submissions
get checked against the latest meta-schemas.

Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
---
 Documentation/devicetree/bindings/Makefile | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
index 1df680d07461..9f2e64e29d79 100644
--- a/Documentation/devicetree/bindings/Makefile
+++ b/Documentation/devicetree/bindings/Makefile
@@ -3,6 +3,16 @@ DT_DOC_CHECKER ?= dt-doc-validate
 DT_EXTRACT_EX ?= dt-extract-example
 DT_MK_SCHEMA ?= dt-mk-schema
 
+DT_SCHEMA_MIN_VERSION = 2020.04
+ifeq (1,$(shell \
+	printf "%s\n" \
+		$(DT_SCHEMA_MIN_VERSION) \
+		$$($(DT_DOC_CHECKER) --version 2>/dev/null || echo 0) | sort -VC; \
+		echo $$? \
+	))
+$(error dtschema minimum version is v$(DT_SCHEMA_MIN_VERSION))
+endif
+
 quiet_cmd_chk_binding = CHKDT   $(patsubst $(srctree)/%,%,$<)
       cmd_chk_binding = $(DT_DOC_CHECKER) -u $(srctree)/$(src) $< ; \
                         $(DT_EXTRACT_EX) $< > $@
-- 
2.20.1