At present, the fdt_subnode_offset() and fdt_path_offset() functions
in libfdt require the exact name of the nodes in question be passed,
including unit address.
This is contrary to traditional OF-like finddevice() behaviour, which
allows the unit address to be omitted (which is useful when the device
name is unambiguous without the address).
This patch introduces similar behaviour to
fdt_subnode_offset_namelen(), and hence to fdt_subnode_offset() and
fdt_path_offset() which are implemented in terms of the former. The
unit address can be omitted from the given node name. If this is
ambiguous, the first such node in the flattened tree will be selected
(this behaviour is consistent with IEEE1275 which specifies only that
an arbitrary node matching the given information be selected).
This very small change is then followed by many more diffs which
change the test examples and testcases to exercise this behaviour.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This large patch removes all trailing whitespace from dtc (including
libfdt, the testsuite and documentation). It also removes a handful
of redundant blank lines (at the end of functions, or when there are
two blank lines together for no particular reason).
As well as anything else, this means that quilt won't whinge when I go
to convert the whole of libfdt into a patch to apply to the kernel.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
As a read-only functions, which take a const pointer to the fdt, treat
fdt_get_property() and fdt_getprop() as returning const pointers to
within the blob. fdt_get_property_w() and fdt_getprop_w() versions
are supplied which take a non-const fdt pointer and return a non-const
pointer for the benefit of callers wishing to alter the device tree
contents.
Likewise the lower-level fdt_offset_ptr() and _fdt_offset_ptr()
functions are changed to return const pointers, with *_w() versions
supplied.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
At present fdt.h #includes stdint.h. This makes some sense, because fdt.h
uses the standard fixed-width integer types. However, this can make life
difficult when building in different environments which may not have a
stdint.h. Therefore, this patch removes the #include from fdt.h, instead
requiring that users of fdt.h define the fixed-width integer types before
including fdt.h, either by themselves including stdint.h, or by any other
means.
At present, libfdt functions returning a structure offset return a
zero-or-positive offset on success, and return a negative error code
on failure. Functions which only return an error code return a
positive version of the error code, or 0 on success.
This patch improves consistency by always returning negative error
codes on failure, for both types of function. With this change, we do
away with the special fdt_offset_error() macro for checking whether a
returned offset value is an error and extracting the encoded error
value within. Instead an explicit (ret_value < 0) is now the
preferred way of checking return values for both offset-returning and
error-code-returning functions.
The fdt_strerror() function in the test code is updated
correspondingly to make more sense with the new conventions.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch abolishes the non-standard and confusing encoding of errors
into pointer return values. The only functions still returning such a
potentially encoded pointer are fdt_get_property() and fdt_getprop().
Those functions also return a length via an (int *). With this patch
those functions instead now return NULL on any error, and return the
code indicating the type of error in the length paramater.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
At present, the blob containing a device tree is passed to the various
fdt_*() functions as a (struct fdt_header *) i.e. a pointer to the
header structure at the beginning of the blob.
This patch changes all the functions so that they instead take a (void
*) pointing to the blob. Under some circumstances can avoid the need
for the caller to cast a blob pointer into a (struct fdt_header *)
before passing it to the fdt_*() functions.
Using a (void *) also reduce the temptation for users of the library
to directly dereference toe (struct fdt_header *) to access header
fields. Instead they must use the fdt_get_header() or
fdt_set_header() macros, or the fdt_magic(), fdt_totalsize()
etc. wrappers around them which are safer, since they will always
handle endian conversion.
With this change, the whole-tree moving, or manipulating functions:
fdt_move(), fdt_open_into() and fdt_pack() no longer need to return a
pointer to the "new" tree. The given (void *) buffer pointer they
take can instead be used directly by the caller as the new tree.
Those functions are thus changed to instead return an error code
(which in turn reduces the number of functions using the ugly encoding
of error values into pointers).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
fdt_property_offset() is the only function in the library returning a
direct offset to a property, and no function takes such an offset
(they only take offsets to nodes, not properties). Furthermore the
only client uses for this function I can think of involve immediately
translating the offset into a pointer, effectively duplicating the
internal function _fdt_getprop()
This function abolishes fdt_property_offset(), replacing it with
fdt_get_property(), a renamed and now externally visible version of
_fdt_getprop().
David Gibson