Enabling -Wcast-qual warnings in dtc shows up a number of places where
we are incorrectly discarding a const qualification.  There are also
some places where we are intentionally discarding the 'const', and we
need an ugly cast through uintptr_t to suppress the warning.  However,
most of these are pretty well isolated with the *_w() functions.  So
in the interests of maximum safety with const qualifications, this
patch enables the warnings and fixes the existing complaints.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Acked-by: NGerald Van Baren <vanbaren@cideas.com>

This patch turns on the -Wpointer-arith option in the dtc Makefile,
and fixes the resulting warnings due to using (void *) in pointer
arithmetic.  While convenient, pointer arithmetic on void * is not
portable, so it's better that we avoid it, particularly in libfdt.

Also add necessary definition of uintptr_t needed by David Gibson's
changeset "dtc: Enable and fix -Wpointer-arith warnings" (the definition
comes from stdint.h, which u-boot doesn't have). -- gvb
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NGerald Van Baren <vanbaren@cideas.com>

This patch makes a couple of small cleanups to parameter checking of
libfdt functions.

	- In several functions which take a node offset, we use an
idiom involving fdt_next_tag() first to check that we have indeed been
given a node offset.  This patch adds a helper function
_fdt_check_node_offset() to encapsulate this usage of fdt_next_tag().

	- In fdt_rw.c in several places we have the expanded version
of the RW_CHECK_HEADER() macro for no particular reason.  This patch
replaces those instances with an invocation of the macro; that's what
it's for.

	- In fdt_sw.c we rename the check_header_sw() function to
sw_check_header() to match the analgous function in fdt_rw.c, and we
provide an SW_CHECK_HEADER() wrapper macro as RW_CHECK_HEADER()
functions in fdt_rw.c
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Currently the CHECK_HEADER() macro is defined local to fdt_ro.c.
However, there are a handful of functions (fdt_move, rw_check_header,
fdt_open_into) from other files which could also use it (currently
they open-code something more-or-less identical).  Therefore, this
patch moves CHECK_HEADER() to libfdt_internal.h and uses it in those
places.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Update libfdt to commit 8eaf5e358366017aa2e846c5038d1aa19958314e from
the device tree compiler (dtc) project.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Enhanced the formerly private function _fdt_next_tag() to allow stepping
  through the tree, used to produce a human-readable dump, and made
  it part of the published interface.
Also added some comments.

This adds the applicable libfdt source files (unmodified) and a README
to explain where the source came from.