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>

diff --git a/.gitignore b/.gitignore
index 97ba6b7..a20ac26 100644 (file)
--- a/.gitignore
+++ b/.gitignore
@@ -15,6 +15,7 @@
 *.bin
 *.bz2
 *.c.[012]*.*
+*.dt.yaml
 *.dtb
 *.dtb.S
 *.dwo

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 2ca77ad..9786957 100644 (file)
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -2,7 +2,7 @@
 # Makefile for Sphinx documentation
 #
 
-subdir-y :=
+subdir-y := devicetree/bindings/
 
 # You can set these variables from the command line.
 SPHINXBUILD   = sphinx-build

diff --git a/Documentation/devicetree/bindings/.gitignore b/Documentation/devicetree/bindings/.gitignore
new file mode 100644 (file)
index 0000000..ef82fcf
--- /dev/null
+++ b/Documentation/devicetree/bindings/.gitignore
@@ -0,0 +1,2 @@
+*.example.dts
+processed-schema.yaml

diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
new file mode 100644 (file)
index 0000000..6e5cef0
--- /dev/null
+++ b/Documentation/devicetree/bindings/Makefile
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+DT_DOC_CHECKER ?= dt-doc-validate
+DT_EXTRACT_EX ?= dt-extract-example
+DT_MK_SCHEMA ?= dt-mk-schema
+DT_MK_SCHEMA_FLAGS := $(if $(DT_SCHEMA_FILES), -u)
+
+quiet_cmd_chk_binding = CHKDT   $(patsubst $(srctree)/%,%,$<)
+      cmd_chk_binding = $(DT_DOC_CHECKER) $< ; \
+                        $(DT_EXTRACT_EX) $< > $@
+
+$(obj)/%.example.dts: $(src)/%.yaml FORCE
+       $(call if_changed,chk_binding)
+
+DT_TMP_SCHEMA := processed-schema.yaml
+extra-y += $(DT_TMP_SCHEMA)
+
+quiet_cmd_mk_schema = SCHEMA  $@
+      cmd_mk_schema = $(DT_MK_SCHEMA) $(DT_MK_SCHEMA_FLAGS) -o $@ $(filter-out FORCE, $^)
+
+DT_DOCS = $(shell cd $(srctree)/$(src) && find * -name '*.yaml')
+DT_SCHEMA_FILES ?= $(addprefix $(src)/,$(DT_DOCS))
+
+extra-y += $(patsubst $(src)/%.yaml,%.example.dts, $(DT_SCHEMA_FILES))
+extra-y += $(patsubst $(src)/%.yaml,%.example.dtb, $(DT_SCHEMA_FILES))
+
+$(obj)/$(DT_TMP_SCHEMA): $(DT_SCHEMA_FILES) FORCE
+       $(call if_changed,mk_schema)

diff --git a/Makefile b/Makefile
index 2f36db8..a3e2db2 100644 (file)
--- 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' \

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 8fe4468..723b33c 100644 (file)
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -61,6 +61,11 @@ real-obj-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))
 extra-y                                += $(dtb-y)
 extra-$(CONFIG_OF_ALL_DTBS)    += $(dtb-)
 
+ifneq ($(CHECK_DTBS),)
+extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y))
+extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-))
+endif
+
 # Add subdir path
 
 extra-y                := $(addprefix $(obj)/,$(extra-y))
@@ -284,13 +289,28 @@ $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
 quiet_cmd_dtc = DTC     $@
 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
        $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
-       $(DTC) -O dtb -o $@ -b 0 \
+       $(DTC) -O $(2) -o $@ -b 0 \
                $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
                -d $(depfile).dtc.tmp $(dtc-tmp) ; \
        cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
 
 $(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
-       $(call if_changed_dep,dtc)
+       $(call if_changed_dep,dtc,dtb)
+
+DT_CHECKER ?= dt-validate
+DT_BINDING_DIR := Documentation/devicetree/bindings
+DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.yaml
+
+quiet_cmd_dtb_check =  CHECK   $@
+      cmd_dtb_check =  $(DT_CHECKER) -p $(DT_TMP_SCHEMA) $@ ;
+
+define rule_dtc_dt_yaml
+       $(call cmd_and_fixdep,dtc,yaml)         \
+       $(call echo-cmd,dtb_check) $(cmd_dtb_check)
+endef
+
+$(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
+       $(call if_changed_rule,dtc_dt_yaml)
 
 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
 

diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile
index 056d5da..5f227d8 100644 (file)
--- a/scripts/dtc/Makefile
+++ b/scripts/dtc/Makefile
@@ -12,6 +12,10 @@ dtc-objs     += dtc-lexer.lex.o dtc-parser.tab.o
 HOST_EXTRACFLAGS := -I$(src)/libfdt
 
 ifeq ($(wildcard /usr/include/yaml.h),)
+ifneq ($(CHECK_DTBS),)
+$(error dtc needs libyaml for DT schema validation support. \
+       Install the necessary libyaml development package.)
+endif
 HOST_EXTRACFLAGS += -DNO_YAML
 else
 dtc-objs       += yamltree.o