| Message ID | 1362506797-21905-1-git-send-email-swarren@wwwdotorg.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/05/2013 12:06 PM, 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, most 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 -> ../../../../../include/dt-bindings > > Some headers used by device tree files may not be useful to the kernel; > they may be used simply to aid in constructing the DT file (e.g. macros > to create a node), but not define any information that the kernel needs > to share. These may be placed directly into arch/*/boot/dts/ along with > the DT files themselves. > > Cc: Hiroshi Doyu <hdoyu@nvidia.com> > Acked-by: Michal Marek <mmarek@suse.cz> > Acked-by: Shawn Guo <shawn.guo@linaro.org> > Signed-off-by: Stephen Warren <swarren@nvidia.com> > --- > Grant, Rob, > > This is a pre-requisite for people to convert their *.dts files to use > cpp, and hence is likely to be useful for a number of ARM subarch trees. > Perhaps this patch can be placed into a standalone topic branch in the > DT repo so we can all merge it. Assuming this patch is OK, I would also > repost the patches that create common headers defining IRQ, and GPIO > flags, which would place files into the new include/dt-bindings > directory. This looks fine to me. As all these will all be arm-soc branches with the dependency, it probably makes more sense for Arnd/Olof to apply this and create the branch for this single patch. Acked-by: Rob Herring <rob.herring@calxeda.com> Rob > > v2: > * Leave arch/*/boot/dts in dtc include path, for any headers that are > only included by *.dts and don't need to be shared by the kernel. > * Fix pathname in commit description. > --- > arch/arm/boot/dts/include/dt-bindings | 1 + > scripts/Makefile.lib | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > 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..af35521 100644 > --- a/scripts/Makefile.lib > +++ b/scripts/Makefile.lib > @@ -158,7 +158,7 @@ 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 >
On 03/05/2013 11:55 PM, Rob Herring wrote: > On 03/05/2013 12:06 PM, 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, most 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 -> ../../../../../include/dt-bindings >> >> Some headers used by device tree files may not be useful to the kernel; >> they may be used simply to aid in constructing the DT file (e.g. macros >> to create a node), but not define any information that the kernel needs >> to share. These may be placed directly into arch/*/boot/dts/ along with >> the DT files themselves. >> >> Cc: Hiroshi Doyu <hdoyu@nvidia.com> >> Acked-by: Michal Marek <mmarek@suse.cz> >> Acked-by: Shawn Guo <shawn.guo@linaro.org> >> Signed-off-by: Stephen Warren <swarren@nvidia.com> >> --- >> Grant, Rob, >> >> This is a pre-requisite for people to convert their *.dts files to use >> cpp, and hence is likely to be useful for a number of ARM subarch trees. >> Perhaps this patch can be placed into a standalone topic branch in the >> DT repo so we can all merge it. Assuming this patch is OK, I would also >> repost the patches that create common headers defining IRQ, and GPIO >> flags, which would place files into the new include/dt-bindings >> directory. > > This looks fine to me. As all these will all be arm-soc branches with > the dependency, it probably makes more sense for Arnd/Olof to apply this > and create the branch for this single patch. OK, that'd work fine for me too. I expect that arm-soc branch would also include the few patches to create some common headers, once I repost.
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..af35521 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -158,7 +158,7 @@ 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