[PATCH v3] kbuild: Add support for DT binding schema checks

Rob Herring
2018-12-10T20:32:31Z

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 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>
Cc: 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>
---
v3:
- Fix error causing only 1st schema file to get used.
- Add a more useful error message when dtc is missing YAML support
telling the user they need to install libyaml devel package.

.gitignore | 1 +
Documentation/Makefile | 2 +-
Documentation/devicetree/bindings/.gitignore | 1 +
Documentation/devicetree/bindings/Makefile | 33 +++++++++++++++++
Makefile | 11 ++++--
scripts/Makefile.lib | 37 ++++++++++++++++++--
6 files changed, 80 insertions(+), 5 deletions(-)
create mode 100644 Documentation/devicetree/bindings/.gitignore
create mode 100644 Documentation/devicetree/bindings/Makefile

diff --git a/.gitignore b/.gitignore
index 97ba6b79834c..a20ac26aa2f5 100644
--- 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 2ca77ad0f238..9786957c6a35 100644
--- 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
index 000000000000..d9194c02dd08
--- /dev/null
+++ b/Documentation/devicetree/bindings/.gitignore
@@ -0,0 +1 @@
+*.example.dts
diff --git a/Documentation/devicetree/bindings/Makefile b/Documentation/devicetree/bindings/Makefile
new file mode 100644
index 000000000000..43f8657ab070
--- /dev/null
+++ b/Documentation/devicetree/bindings/Makefile
@@ -0,0 +1,33 @@
+# 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 $<
+ cmd_chk_binding = (set -e; \
+ $(DT_DOC_CHECKER) $< ; \
+ mkdir -p $(dir $@) ; \
+ $(DT_EXTRACT_EX) $< > $@ )
+
+$(obj)/%.example.dts: $(src)/%.yaml FORCE
+ $(call if_changed,chk_binding)
+
+DT_TMP_SCHEMA := .schema.yaml.tmp
+extra-y += $(DT_TMP_SCHEMA)
+
+quiet_cmd_mk_schema = SCHEMA $@
+ cmd_mk_schema = mkdir -p $(obj); \
+ rm -f $@; \
+ $(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): | $(addprefix $(obj)/,$(patsubst $(src)/%.yaml,%.example.dtb, $(DT_SCHEMA_FILES)))
+
+$(obj)/$(DT_TMP_SCHEMA): $(addprefix $(srctree)/, $(DT_SCHEMA_FILES)) FORCE
+ $(call if_changed,mk_schema)
diff --git a/Makefile b/Makefile
index 2f36db897895..ff59adf43300 100644
--- a/Makefile
+++ b/Makefile
@@ -1232,10 +1232,13 @@ ifneq ($(dtstree),)
%.dtb: prepare3 scripts_dtc
$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@

-PHONY += dtbs dtbs_install
+PHONY += dtbs dtbs_install dt_binding_check
dtbs: prepare3 scripts_dtc
$(Q)$(MAKE) $(build)=$(dtstree)

+dtbs_check: prepare3 dt_binding_check
+ $(Q)$(MAKE) $(build)=$(dtstree) CHECK_DTBS=1
+
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 8fe4468f9bda..6a3450b20041 100644
--- 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 +289,41 @@ $(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)/.schema.yaml.tmp
+
+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
+
+cmd_dtc_yaml_chk = \
+ if ! echo "/dts-v1/; /{};" | $(DTC) -I dts -O yaml > /dev/null ; then \
+ echo "*"; \
+ echo "* dtc needs libyaml for DT schema validation support."; \
+ echo "* Install the necessary libyaml development package from your distro."; \
+ echo "*"; \
+ false; \
+ fi; \
+ touch $@
+
+$(objtree)/scripts/dtc/.dtc-yaml-chk.tmp: $(DTC) FORCE
+ $(call if_changed,dtc_yaml_chk)
+
+$(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE | $(objtree)/scripts/dtc/.dtc-yaml-chk.tmp
+ $(call if_changed_rule,dtc_dt_yaml)

dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)

--
2.19.1