pylibfdt: move pylibfdt to scripts/dtc/pylibfdt and refactor makefile

The pylibfdt is used by dtoc (and, indirectly by binman), but there
is no reason why it must be generated in the tools/ directory.

Recently, U-Boot switched over to the bundled DTC, and the directory
structure under scripts/dtc/ now mirrors the upstream DTC project.
So, scripts/dtc/pylibfdt is the best location.

I also rewrote the Makefile in a cleaner Kbuild style.

The scripts from the upstream have been moved as follows:

  lib/libfdt/pylibfdt/setup.py -> scripts/dtc/pylibfdt/setup.py
  lib/libfdt/pylibfdt/libfdt.i -> scripts/dtc/pylibfdt/libfdt.i_shipped

The .i_shipped is coped to .i during building because the .i must be
located in the objtree when we build it out of tree.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/tools/.gitignore b/tools/.gitignore
index 5293d44..6a487d2 100644
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -1,4 +1,3 @@
-/_libfdt.so
 /atmel_pmecc_params
 /bin2header
 /bmp_logo
@@ -17,9 +16,6 @@
 /img2srec
 /kwboot
 /lib/
-/libfdt.py
-/libfdt.pyc
-/libfdt_wrap.c
 /mips-relocs
 /mkenvimage
 /mkexynosspl
diff --git a/tools/Makefile b/tools/Makefile
index 5db2a54..2b87e18 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -63,15 +63,6 @@
 			fdt_empty_tree.c fdt_addresses.c fdt_overlay.c \
 			fdt_region.c
 
-# Unfortunately setup.py below cannot handle srctree being ".." which it often
-# is. It fails with an error like:
-# Fatal error: can't create build/temp.linux-x86_64-2.7/../lib/libfdt/fdt.o:
-#    No such file or directory
-# To fix this, use an absolute path.
-libfdt_tree := $(shell readlink -f $(srctree)/lib/libfdt)
-
-LIBFDT_SRCS := $(addprefix $(libfdt_tree)/, $(LIBFDT_CSRCS))
-LIBFDT_SWIG := $(addprefix $(libfdt_tree)/, pylibfdt/libfdt.i)
 LIBFDT_OBJS := $(addprefix lib/libfdt/, $(patsubst %.c, %.o, $(LIBFDT_CSRCS)))
 
 RSA_OBJS-$(CONFIG_FIT_SIGNATURE) := $(addprefix lib/rsa/, \
@@ -123,23 +114,6 @@
 fit_info-objs   := $(dumpimage-mkimage-objs) fit_info.o
 fit_check_sign-objs   := $(dumpimage-mkimage-objs) fit_check_sign.o
 
-# Unfortunately setup.py (or actually the Python distutil implementation)
-# puts files into the same directory as the .i file. We cannot touch the source
-# directory, so we copy the .i file into the tools/ build subdirectory before
-# calling setup. This directory is safe to write to. This ensures that we get
-# all three files in $(obj)/tools: _libfdt.so, libfdt.py and libfdt_wrap.c
-# The latter is a temporary file which we could actually remove.
-tools/_libfdt.so: $(LIBFDT_SRCS) $(LIBFDT_SWIG)
-	$(Q)cp $(LIBFDT_SWIG) tools/.
-	$(Q)unset CC; \
-	unset CROSS_COMPILE; \
-	LDFLAGS="$(HOSTLDFLAGS)" CFLAGS= VERSION="u-boot-$(UBOOTVERSION)" \
-		CPPFLAGS="$(_hostc_flags)" OBJDIR=tools \
-		SOURCES="$(LIBFDT_SRCS) tools/libfdt.i" \
-		SWIG_OPTS="-I$(srctree)/lib/libfdt -I$(srctree)/lib" \
-		$(PYTHON) $(libfdt_tree)/pylibfdt/setup.py --quiet build_ext \
-			--build-lib tools
-
 ifneq ($(CONFIG_MX23)$(CONFIG_MX28),)
 # Add CONFIG_MXS into host CFLAGS, so we can check whether or not register
 # the mxsimage support within tools/mxsimage.c .
@@ -231,10 +205,6 @@
 
 always := $(hostprogs-y)
 
-# Build a libfdt Python module if swig is available
-# Use 'sudo apt-get install swig libpython-dev' to enable this
-always += $(if $(shell which swig 2> /dev/null),_libfdt.so)
-
 # Generated LCD/video logo
 LOGO_H = $(objtree)/include/bmp_logo.h
 LOGO_DATA_H = $(objtree)/include/bmp_logo_data.h
diff --git a/tools/binman/binman.py b/tools/binman/binman.py
index 09dc36a..e75a59d 100755
--- a/tools/binman/binman.py
+++ b/tools/binman/binman.py
@@ -21,7 +21,7 @@
     sys.path.insert(0, os.path.join(our_path, dirname))
 
 # Bring in the libfdt module
-sys.path.insert(0, 'tools')
+sys.path.insert(0, 'scripts/dtc/pylibfdt')
 
 # Also allow entry-type modules to be brought in from the etype directory.
 sys.path.insert(0, os.path.join(our_path, 'etype'))