[PATCH v3] 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>
---
v3:
 - Drop leading '0' in version month
 - Rework with Masahiro's shell commands

v2:
 - Use a build rule for the version check instead
---
 Documentation/devicetree/bindings/Makefile | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
index 1df680d07461..67b0969281da 100644
--- a/Documentation/devicetree/bindings/Makefile
+++ b/Documentation/devicetree/bindings/Makefile
@@ -3,11 +3,19 @@ DT_DOC_CHECKER ?= dt-doc-validate
 DT_EXTRACT_EX ?= dt-extract-example
 DT_MK_SCHEMA ?= dt-mk-schema
 
+DT_SCHEMA_MIN_VERSION = 2020.4
+
+PHONY += check_dtschema_version
+check_dtschema_version:
+	@{ echo $(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)" >&2; false; }
+
 quiet_cmd_chk_binding = CHKDT   $(patsubst $(srctree)/%,%,$<)
       cmd_chk_binding = $(DT_DOC_CHECKER) -u $(srctree)/$(src) $< ; \
                         $(DT_EXTRACT_EX) $< > $@
 
-$(obj)/%.example.dts: $(src)/%.yaml FORCE
+$(obj)/%.example.dts: $(src)/%.yaml check_dtschema_version FORCE
 	$(call if_changed,chk_binding)
 
 # Use full schemas when checking %.example.dts
@@ -34,11 +42,11 @@ override DTC_FLAGS := \
 	-Wno-avoid_unnecessary_addr_size \
 	-Wno-graph_child_address
 
-$(obj)/processed-schema-examples.yaml: $(DT_DOCS) FORCE
+$(obj)/processed-schema-examples.yaml: $(DT_DOCS) check_dtschema_version FORCE
 	$(call if_changed,mk_schema)
 
 $(obj)/processed-schema.yaml: DT_MK_SCHEMA_FLAGS := -u
-$(obj)/processed-schema.yaml: $(DT_SCHEMA_FILES) FORCE
+$(obj)/processed-schema.yaml: $(DT_SCHEMA_FILES) check_dtschema_version FORCE
 	$(call if_changed,mk_schema)
 
 extra-y += processed-schema.yaml
-- 
2.20.1