[PATCH] kbuild: create an "include chroot" for DT bindings

[mmarek@suse.cz (Michal Marek)]

On 20.2.2013 22:05, Stephen Warren wrote:
> From: Stephen Warren <swarren@nvidia.com>
> 
> 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.

Nice trick. dts+cpp only sees the bindings and LINUXINCLUDE is not
polluted either. You can add

Acked-by: Michal Marek <mmarek@suse.cz>

if you like.

Michal