From: Stephen Warren <swarren@xxxxxxxxxx> The recent dtc+cpp support allows header files and C pre-processor defines/macros to be used when compiling device tree files. These headers will typically define various constants that are part of the device tree bindings. The original patch which set up the dtc+cpp include path only considered using those headers from device tree files. However, they are also useful for kernel code which needs to interpret the device tree. In both the DT files and the kernel, I'd like to include the DT-related headers in the same way, for example, <dt-bindings/gpio/tegra-gpio.h>. That will simplify any text which discusses the DT header locations. Creating a <dt-bindings/> for kernel source to use is as simple as placing files into include/dt-bindings/. However, when compiling DT files, the include path should be restricted so that only the dt-bindings path is available; arbitrary kernel headers shouldn't be exposed. For this reason, create a specific include directory for use by dtc+cpp, and symlink dt-bindings from there to the actual location of include/dt-bindings/. For want of a better location, place this "include chroot" into the existing dts/ directory. arch/*/boot/dts/include/dt-bindings -> ../../../../../dt-bindings Cc: Shawn Guo <shawn.guo@xxxxxxxxxx> Cc: Hiroshi Doyu <hdoyu@xxxxxxxxxx> Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx> --- You can find an example of how this would be used at git://nv-tegra.nvidia.com/user/swarren/linux-2.6 linux-next_common (note: there's a bunch of other cruft in that branch too) arch/arm/boot/dts/include/dt-bindings | 1 + scripts/Makefile.lib | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-) create mode 120000 arch/arm/boot/dts/include/dt-bindings diff --git a/arch/arm/boot/dts/include/dt-bindings b/arch/arm/boot/dts/include/dt-bindings new file mode 120000 index 0000000..08c00e4 --- /dev/null +++ b/arch/arm/boot/dts/include/dt-bindings @@ -0,0 +1 @@ +../../../../../include/dt-bindings \ No newline at end of file diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 07125e6..d6c5036 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -157,8 +157,7 @@ cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ ld_flags = $(LDFLAGS) $(ldflags-y) dtc_cpp_flags = -Wp,-MD,$(depfile) -nostdinc \ - -I$(srctree)/arch/$(SRCARCH)/boot/dts \ - -I$(srctree)/arch/$(SRCARCH)/include/dts \ + -I$(srctree)/arch/$(SRCARCH)/boot/dts/include \ -undef -D__DTS__ # Finds the multi-part object the current object will be linked into -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
