[PATCH V3 0/2] dtc: enable use of pre-processor

[PATCH V3 0/2] dtc: enable use of pre-processor

[Stephen Warren]

From: Stephen Warren <swarren@nvidia.com>

This series adds a build rule to run cpp on *.dtsp prior to invoking dtc.

This patch relies on the patch I recently posted to update the in-kernel
copy of dtc to match the latest upstream version ("[PATCH] dtc: import
latest upstream dtc"; http://www.spinics.net/lists/kernel/msg1410063.html.

Stephen Warren (2):
  kbuild: centralize .dts->.dtb rule
  kbuild: introduce cmd_dtc_cpp

 arch/arm/boot/Makefile           |    4 ----
 arch/arm/boot/dts/skeleton.dtsip |   13 +++++++++++++
 arch/c6x/boot/Makefile           |    3 ---
 arch/openrisc/boot/Makefile      |    3 ---
 arch/powerpc/boot/Makefile       |    4 ----
 scripts/Makefile.lib             |    9 +++++++++
 6 files changed, 22 insertions(+), 14 deletions(-)
 create mode 100644 arch/arm/boot/dts/skeleton.dtsip

[PATCH V3 1/2] kbuild: centralize .dts->.dtb rule

[Stephen Warren]

From: Stephen Warren <swarren@nvidia.com>

All architectures that use cmd_dtc do so in the same way. Move the build
rule to a central location to avoid duplication.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
v3: No change.
v2: New patch.
---
 arch/arm/boot/Makefile      |    4 ----
 arch/c6x/boot/Makefile      |    3 ---
 arch/openrisc/boot/Makefile |    3 ---
 arch/powerpc/boot/Makefile  |    4 ----
 scripts/Makefile.lib        |    3 +++
 5 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/arch/arm/boot/Makefile b/arch/arm/boot/Makefile
index 3fdab01..da33331 100644
--- a/arch/arm/boot/Makefile
+++ b/arch/arm/boot/Makefile
@@ -61,10 +61,6 @@ endif
 
 targets += $(dtb-y)
 
-# Rule to build device tree blobs
-$(obj)/%.dtb: $(src)/dts/%.dts FORCE
-	$(call if_changed_dep,dtc)
-
 $(obj)/dtbs: $(addprefix $(obj)/, $(dtb-y))
 
 clean-files := *.dtb
diff --git a/arch/c6x/boot/Makefile b/arch/c6x/boot/Makefile
index 6891257..ad605fb 100644
--- a/arch/c6x/boot/Makefile
+++ b/arch/c6x/boot/Makefile
@@ -12,9 +12,6 @@ ifneq ($(DTB),)
 obj-y += linked_dtb.o
 endif
 
-$(obj)/%.dtb: $(src)/dts/%.dts FORCE
-	$(call if_changed_dep,dtc)
-
 quiet_cmd_cp = CP      $< $@$2
 	cmd_cp = cat $< >$@$2 || (rm -f $@ && echo false)
 
diff --git a/arch/openrisc/boot/Makefile b/arch/openrisc/boot/Makefile
index 0995835..fd329bd 100644
--- a/arch/openrisc/boot/Makefile
+++ b/arch/openrisc/boot/Makefile
@@ -10,6 +10,3 @@ obj-y += $(BUILTIN_DTB)
 clean-files := *.dtb.S
 
 #DTC_FLAGS ?= -p 1024
-
-$(obj)/%.dtb: $(src)/dts/%.dts FORCE
-	$(call if_changed_dep,dtc)
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 6a15c96..90206f2 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -356,10 +356,6 @@ $(obj)/treeImage.initrd.%: vmlinux $(obj)/%.dtb $(wrapperbits)
 $(obj)/treeImage.%: vmlinux $(obj)/%.dtb $(wrapperbits)
 	$(call if_changed,wrap,treeboot-$*,,$(obj)/$*.dtb)
 
-# Rule to build device tree blobs
-$(obj)/%.dtb: $(src)/dts/%.dts FORCE
-	$(call if_changed_dep,dtc)
-
 # If there isn't a platform selected then just strip the vmlinux.
 ifeq (,$(image-y))
 image-y := vmlinux.strip
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 0be6f11..425578e 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -266,6 +266,9 @@ $(obj)/%.dtb.S: $(obj)/%.dtb
 quiet_cmd_dtc = DTC     $@
 cmd_dtc = $(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) -d $(depfile) $<
 
+$(obj)/%.dtb: $(src)/dts/%.dts FORCE
+	$(call if_changed_dep,dtc)
+
 # Bzip2
 # ---------------------------------------------------------------------------
 
-- 
1.7.0.4

[PATCH V3 2/2] kbuild: introduce cmd_dtc_cpp

[Stephen Warren]

From: Stephen Warren <swarren@nvidia.com>

cmd_dtc_cpp runs the C pre-processor on the input .dts file before
passing it to dtc for final compilation. This allows used of #define
within the .dts file.

Introduce a new rule for %.dtsp -> %.dtb, which uses cmd_dtc_cpp. A new
file extension is introduced for this purpose, since use of the pre-
processor must be optional; any property or node name that starts with
"#" must be escaped to prevent the pre-processor attempting to interpret
it as a directive. For this reason, skeleton.dtsi-cpp is introduced for
*.dts-cpp to include.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
v3: Pass "-x c" not "-xc" to cpp.
v2: Place make %.dtb: %.dtsp rule into Makefile.lib.
---
 arch/arm/boot/dts/skeleton.dtsip |   13 +++++++++++++
 scripts/Makefile.lib             |    6 ++++++
 2 files changed, 19 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/boot/dts/skeleton.dtsip

diff --git a/arch/arm/boot/dts/skeleton.dtsip b/arch/arm/boot/dts/skeleton.dtsip
new file mode 100644
index 0000000..8bf6729
--- /dev/null
+++ b/arch/arm/boot/dts/skeleton.dtsip
@@ -0,0 +1,13 @@
+/*
+ * Skeleton device tree; the bare minimum needed to boot; just include and
+ * add a compatible value.  The bootloader will typically populate the memory
+ * node.
+ */
+
+/ {
+	\#address-cells = <1>;
+	\#size-cells = <1>;
+	chosen { };
+	aliases { };
+	memory { device_type = "memory"; reg = <0 0>; };
+};
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 425578e..1980078 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -269,6 +269,12 @@ cmd_dtc = $(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) -d $(depfile
 $(obj)/%.dtb: $(src)/dts/%.dts FORCE
 	$(call if_changed_dep,dtc)
 
+quiet_cmd_dtc_cpp = DTC+CPP $@
+cmd_dtc_cpp = $(CC) -E -Wp,-MD,$(depfile) -x c $< | $(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) -
+
+$(obj)/%.dtb: $(src)/dts/%.dtsp FORCE
+	$(call if_changed_dep,dtc_cpp)
+
 # Bzip2
 # ---------------------------------------------------------------------------
 
-- 
1.7.0.4