dt-bindings: copy process-schema-examples.yaml to process-schema.yaml

There are two processed schema files:

 - processed-schema-examples.yaml

    Used for 'make dt_binding_check'. This is always a full schema.

 - processed-schema.yaml

    Used for 'make dtbs_check'. This may be a full schema, or a smaller
    subset if DT_SCHEMA_FILES is given by a user.

If DT_SCHEMA_FILES is not specified, they are the same. You can copy
the former to the latter instead of running dt-mk-schema twice. This
saves the cpu time a lot when you do 'make dt_binding_check dtbs_check'
because building the full schema takes a couple of seconds.

If DT_SCHEMA_FILES is specified, processed-schema.yaml is generated
based on the specified yaml files.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20200625170434.635114-4-masahiroy@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

[ upstream commit: dee9c0b ]

Bindings/Makefile

@@ -2,7 +2,6 @@
 DT_DOC_CHECKER ?= dt-doc-validate
 DT_EXTRACT_EX ?= dt-extract-example
 DT_MK_SCHEMA ?= dt-mk-schema
-DT_MK_SCHEMA_USERONLY_FLAG := $(if $(DT_SCHEMA_FILES), -u)
 
 DT_SCHEMA_MIN_VERSION = 2020.5
 
@@ -35,12 +34,6 @@ quiet_cmd_mk_schema = SCHEMA  $@
 
 DT_DOCS = $(shell $(find_cmd) | sed -e 's|^$(srctree)/||')
 
-DT_SCHEMA_FILES ?= $(DT_DOCS)
-
-extra-$(CHECK_DT_BINDING) += $(patsubst $(src)/%.yaml,%.example.dts, $(DT_SCHEMA_FILES))
-extra-$(CHECK_DT_BINDING) += $(patsubst $(src)/%.yaml,%.example.dt.yaml, $(DT_SCHEMA_FILES))
-extra-$(CHECK_DT_BINDING) += processed-schema-examples.yaml
-
 override DTC_FLAGS := \
 	-Wno-avoid_unnecessary_addr_size \
 	-Wno-graph_child_address \
@@ -49,10 +42,29 @@ override DTC_FLAGS := \
 $(obj)/processed-schema-examples.yaml: $(DT_DOCS) check_dtschema_version FORCE
 	$(call if_changed,mk_schema)
 
-$(obj)/processed-schema.yaml: DT_MK_SCHEMA_FLAGS := $(DT_MK_SCHEMA_USERONLY_FLAG)
+ifeq ($(DT_SCHEMA_FILES),)
+
+# Unless DT_SCHEMA_FILES is specified, use the full schema for dtbs_check too.
+# Just copy processed-schema-examples.yaml
+
+$(obj)/processed-schema.yaml: $(obj)/processed-schema-examples.yaml FORCE
+	$(call if_changed,copy)
+
+DT_SCHEMA_FILES = $(DT_DOCS)
+
+else
+
+# If DT_SCHEMA_FILES is specified, use it for processed-schema.yaml
+
+$(obj)/processed-schema.yaml: DT_MK_SCHEMA_FLAGS := -u
 $(obj)/processed-schema.yaml: $(DT_SCHEMA_FILES) check_dtschema_version FORCE
 	$(call if_changed,mk_schema)
 
+endif
+
+extra-$(CHECK_DT_BINDING) += $(patsubst $(src)/%.yaml,%.example.dts, $(DT_SCHEMA_FILES))
+extra-$(CHECK_DT_BINDING) += $(patsubst $(src)/%.yaml,%.example.dt.yaml, $(DT_SCHEMA_FILES))
+extra-$(CHECK_DT_BINDING) += processed-schema-examples.yaml
 extra-$(CHECK_DTBS) += processed-schema.yaml
 
 # Hack: avoid 'Argument list too long' error for 'make clean'. Remove most of