Thomas reported U-Boot failed to build host tools if libfdt-devel
package is installed because tools include libfdt headers from
/usr/include/ instead of using internal ones.

This commit moves the header code:
  include/libfdt.h         -> include/linux/libfdt.h
  include/libfdt_env.h     -> include/linux/libfdt_env.h

and replaces include directives:
  #include <libfdt.h>      -> #include <linux/libfdt.h>
  #include <libfdt_env.h>  -> #include <linux/libfdt_env.h>

Reported-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

The only difference between scripts/dtc/libfdt/fdt_rw.c and
lib/libfdt/fdt_rw.c is fdt_remove_unused_strings().

It is only used by fdtgrep, so we do not need to compile it for U-Boot
image.  Move it to tools/libfdt/fdw_rw.c so that lib/libfdt/fdt_rw.c
can be a wrapper of scripts/dtc/libfdt/fdt_rw.c.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Now, lib/libfdt/fdt_wip.c is the same as scripts/dtc/libfdt/fdt_wip.c

Change the former to a wrapper of the latter.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

lib/libfdt/ and scripts/dtc/libfdt have the same copies for the
followings 6 files:
  fdt.c fdt_addresses.c fdt_empty_tree.c fdt_overlay.c fdt_strerr.c
  fdt_sw.c

Make them a wrapper of scripts/dtc/libfdt/*.  This is exactly what
Linux does to sync libfdt.  In order to make is possible, import
<linux/libfdt.h> and <linux/libfdt_env.h> from Linux 4.14-rc5.

Unfortunately, U-Boot locally modified the following 3 files:
  fdt_ro.c fdt_wip.c fdt_rw.c

The fdt_region.c is U-Boot own file.

I did not touch them in order to avoid unpredictable impact.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

The device tree overlays are a good way to deal with user-modifyable
boards or boards with some kind of an expansion mechanism where we can
easily plug new board in (like the BBB, the Raspberry Pi or the CHIP).

Add a new function to merge overlays with a base device tree.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

A number of style fixes across the files in this directory, including:

 * Correct invalid kernel-doc content.
 * Tidy up massive comment in fdt_region.c.
 * Use correct spelling of "U-Boot".
 * Replace tests of "! <var>" with "!<var>".
 * Replace "libfdt_env.h" with <libfdt_env.h>.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: Simon Glass <sjg@chromium.org>

These have been sent upstream but not accepted to libfdt. For now, bring
these into U-Boot to enable fdtgrep to operate. We will use fdtgrep to
cut device tree files down for SPL.

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

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

This brings in changes up to commit f9e91a48 in the libfdt repo.
Mostly this is whitespace/minor changes. But there are a few new
features:

- fdt_size_cells() and fdt_address_cells()
- fdt_resize()

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

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>