fdt: Move to setuptools

The distutils package is deprecated. The upstream libfdt repo uses
setuptools for building the pylibfdt module, so bring in that code,
suitably modified for U-Boot. Also bring in the README.

The modifications include setting the version correctly, making use of
the environment variables provided by the Makefile and various tweaks
to the directories.

Note that the version omits the minus character at the start of
EXTRAVERSION, since this creates a warning. The build is really just used
within U-Boot itself, so it doesn't matter too much if the version matches
upstream, or exactly matches U-Boot.

Signed-off-by: Simon Glass <sjg@chromium.org>

3 files changed, 158 insertions, 10 deletions

diff --git a/scripts/dtc/README b/scripts/dtc/README
new file mode 100644
index 0000000000..a48312a422
--- /dev/null
+++ b/scripts/dtc/README
@@ -0,0 +1,106 @@
+The source tree contains the Device Tree Compiler (dtc) toolchain for
+working with device tree source and binary files and also libfdt, a
+utility library for reading and manipulating the binary format.
+
+DTC and LIBFDT are maintained by:
+
+David Gibson <david@gibson.dropbear.id.au>
+Jon Loeliger <loeliger@gmail.com>
+
+
+Python library
+--------------
+
+A Python library is also available. To build this you will need to install
+swig and Python development files. On Debian distributions:
+
+   sudo apt-get install swig python3-dev
+
+The library provides an Fdt class which you can use like this:
+
+$ PYTHONPATH=../pylibfdt python3
+>>> import libfdt
+>>> fdt = libfdt.Fdt(open('test_tree1.dtb', mode='rb').read())
+>>> node = fdt.path_offset('/subnode@1')
+>>> print(node)
+124
+>>> prop_offset = fdt.first_property_offset(node)
+>>> prop = fdt.get_property_by_offset(prop_offset)
+>>> print('%s=%s' % (prop.name, prop.as_str()))
+compatible=subnode1
+>>> node2 = fdt.path_offset('/')
+>>> print(fdt.getprop(node2, 'compatible').as_str())
+test_tree1
+
+You will find tests in tests/pylibfdt_tests.py showing how to use each
+method. Help is available using the Python help command, e.g.:
+
+    $ cd pylibfdt
+    $ python3 -c "import libfdt; help(libfdt)"
+
+If you add new features, please check code coverage:
+
+    $ sudo apt-get install python3-coverage
+    $ cd tests
+    # It's just 'coverage' on most other distributions
+    $ python3-coverage run pylibfdt_tests.py
+    $ python3-coverage html
+    # Open 'htmlcov/index.html' in your browser
+
+
+The library can be installed with pip from a local source tree:
+
+    pip install . [--user|--prefix=/path/to/install_dir]
+
+Or directly from a remote git repo:
+
+    pip install git+git://git.kernel.org/pub/scm/utils/dtc/dtc.git@main
+
+The install depends on libfdt shared library being installed on the host system
+first. Generally, using --user or --prefix is not necessary and pip will use the
+default location for the Python installation which varies if the user is root or
+not.
+
+You can also install everything via make if you like, but pip is recommended.
+
+To install both libfdt and pylibfdt you can use:
+
+    make install [PREFIX=/path/to/install_dir]
+
+To disable building the python library, even if swig and Python are available,
+use:
+
+    make NO_PYTHON=1
+
+
+More work remains to support all of libfdt, including access to numeric
+values.
+
+
+Adding a new function to libfdt.h
+---------------------------------
+
+The shared library uses libfdt/version.lds to list the exported functions, so
+add your new function there. Check that your function works with pylibfdt. If
+it cannot be supported, put the declaration in libfdt.h behind #ifndef SWIG so
+that swig ignores it.
+
+
+Tests
+-----
+
+Test files are kept in the tests/ directory. Use 'make check' to build and run
+all tests.
+
+If you want to adjust a test file, be aware that tree_tree1.dts is compiled
+and checked against a binary tree from assembler macros in trees.S. So
+if you change that file you must change tree.S also.
+
+
+Mailing list
+------------
+The following list is for discussion about dtc and libfdt implementation
+mailto:devicetree-compiler@vger.kernel.org
+
+Core device tree bindings are discussed on the devicetree-spec list:
+mailto:devicetree-spec@vger.kernel.org
diff --git a/scripts/dtc/pylibfdt/Makefile b/scripts/dtc/pylibfdt/Makefile
index a7579f0c5f..e442d5c242 100644
--- a/scripts/dtc/pylibfdt/Makefile
+++ b/scripts/dtc/pylibfdt/Makefile
@@ -13,11 +13,14 @@ include $(LIBFDT_srcdir)/Makefile.libfdt
 PYLIBFDT_srcs = $(addprefix $(LIBFDT_srcdir)/,$(LIBFDT_SRCS)) \
 		$(obj)/libfdt.i
 
+# create a version string compliant with PEP 440
+PEP_VERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(subst -,,$(EXTRAVERSION))
+
 quiet_cmd_pymod = PYMOD   $@
       cmd_pymod = unset CROSS_COMPILE; unset CFLAGS; \
 		CC="$(HOSTCC)" LDSHARED="$(HOSTCC) -shared " \
 		LDFLAGS="$(HOSTLDFLAGS)" \
-		VERSION="$(UBOOTVERSION)" \
+		VERSION="$(PEP_VERSION)" \
 		CPPFLAGS="$(HOSTCFLAGS) -I$(LIBFDT_srcdir)" OBJDIR=$(obj) \
 		SOURCES="$(PYLIBFDT_srcs)" \
 		SWIG_OPTS="-I$(LIBFDT_srcdir) -I$(LIBFDT_srcdir)/.." \
diff --git a/scripts/dtc/pylibfdt/setup.py b/scripts/dtc/pylibfdt/setup.py
index 992cdec30f..ec1fc5002b 100755
--- a/scripts/dtc/pylibfdt/setup.py
+++ b/scripts/dtc/pylibfdt/setup.py
@@ -1,11 +1,13 @@
 #!/usr/bin/env python3
+# SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
 
 """
 setup.py file for SWIG libfdt
 Copyright (C) 2017 Google, Inc.
 Written by Simon Glass <sjg@chromium.org>
 
-SPDX-License-Identifier:	GPL-2.0+ BSD-2-Clause
+This script is modified from the upstream version, to fit in with the U-Boot
+build system.
 
 Files to be built into the extension are provided in SOURCES
 C flags to use are provided in CPPFLAGS
@@ -18,14 +20,29 @@ allows this script to be run stand-alone, e.g.:
     ./pylibfdt/setup.py install [--prefix=...]
 """
 
-from distutils.core import setup, Extension
+from setuptools import setup, Extension
+from setuptools.command.build_py import build_py as _build_py
 import os
 import re
 import sys
 
+srcdir = os.path.dirname(__file__)
+
+with open(os.path.join(srcdir, "../README"), "r") as fh:
+    long_description = fh.read()
+
 # Decodes a Makefile assignment line into key and value (and plus for +=)
 RE_KEY_VALUE = re.compile('(?P<key>\w+) *(?P<plus>[+])?= *(?P<value>.*)$')
 
+def get_top_builddir():
+    if '--top-builddir' in sys.argv:
+        index = sys.argv.index('--top-builddir')
+        sys.argv.pop(index)
+        return sys.argv.pop(index)
+    else:
+        return os.path.join(srcdir, '..')
+
+top_builddir = get_top_builddir()
 
 def ParseMakefile(fname):
     """Parse a Makefile to obtain its variables.
@@ -86,7 +103,7 @@ def GetEnvFromMakefiles():
     makevars = ParseMakefile(os.path.join(basedir, 'libfdt', 'Makefile.libfdt'))
     files = makevars['LIBFDT_SRCS'].split()
     files = [os.path.join(basedir, 'libfdt', fname) for fname in files]
-    files.append('pylibfdt/libfdt.i')
+    files.append('libfdt.i')
     cflags = ['-I%s' % basedir, '-I%s/libfdt' % basedir]
     objdir = ''
     return swig_opts, version, files, cflags, objdir
@@ -107,17 +124,39 @@ if not all((swig_opts, version, files, cflags, objdir)):
 
 libfdt_module = Extension(
     '_libfdt',
-    sources = files,
-    extra_compile_args = cflags,
-    swig_opts = swig_opts,
+    sources=files,
+    include_dirs=[os.path.join(srcdir, 'libfdt')],
+    library_dirs=[os.path.join(top_builddir, 'libfdt')],
+    swig_opts=swig_opts,
 )
 
+class build_py(_build_py):
+    def run(self):
+        self.run_command("build_ext")
+        return super().run()
+
 setup(
     name='libfdt',
-    version= version,
-    author='Simon Glass <sjg@chromium.org>',
+    version=version,
+    cmdclass = {'build_py' : build_py},
+    author='Simon Glass',
+    author_email='sjg@chromium.org',
     description='Python binding for libfdt',
     ext_modules=[libfdt_module],
     package_dir={'': objdir},
-    py_modules=['pylibfdt/libfdt'],
+    py_modules=['libfdt'],
+
+    long_description=long_description,
+    long_description_content_type="text/plain",
+    url="https://git.kernel.org/pub/scm/utils/dtc/dtc.git",
+    license="BSD",
+    license_files=["GPL", "BSD-2-Clause"],
+
+    classifiers=[
+        "Programming Language :: Python :: 3",
+        "License :: OSI Approved :: BSD License",
+        "License :: OSI Approved :: GNU General Public License v2 or later (GPLv2+)",
+        "Operating System :: OS Independent",
+    ],
+
 )