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author | David Gibson <david@gibson.dropbear.id.au> | 2009-11-26 07:37:13 +0300 |
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committer | Gerald Van Baren <gvb@unssw.com> | 2011-07-15 05:03:53 +0400 |
commit | 05a22ba096fb996bb69ab020a8d08aafac2c28ba (patch) | |
tree | 8f4019af405604abed59b5e05df4be05f166637d | |
parent | 68d4230c3ccce96a72c5b99e48399bf1796fe3c6 (diff) | |
download | u-boot-05a22ba096fb996bb69ab020a8d08aafac2c28ba.tar.xz |
Support ePAPR compliant phandle properties
Currently, the Linux kernel, libfdt and dtc, when using flattened
device trees encode a node's phandle into a property named
"linux,phandle". The ePAPR specification, however - aiming as it is
to not be a Linux specific spec - requires that phandles be encoded in
a property named simply "phandle".
This patch adds support for this newer approach to dtc and libfdt.
Specifically:
- fdt_get_phandle() will now return the correct phandle if it
is supplied in either of these properties
- fdt_node_offset_by_phandle() will correctly find a node with
the given phandle encoded in either property.
- By default, when auto-generating phandles, dtc will encode
it into both properties for maximum compatibility. A new -H
option allows either only old-style or only new-style
properties to be generated.
- If phandle properties are explicitly supplied in the dts
file, dtc will not auto-generate ones in the alternate format.
- If both properties are supplied, dtc will check that they
have the same value.
- Some existing testcases are updated to use a mix of old and
new-style phandles, partially testing the changes.
- A new phandle_format test further tests the libfdt support,
and the -H option.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This was extracted from the DTC commit:
d75b33af676d0beac8398651a7f09037555a550b Mon Sep 17 00:00:00 2001
Signed-off-by: Gerald Van Baren <vanbaren@cideas.com>
-rw-r--r-- | lib/libfdt/fdt_ro.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c index 1e1e32209c..91a354e108 100644 --- a/lib/libfdt/fdt_ro.c +++ b/lib/libfdt/fdt_ro.c @@ -278,9 +278,14 @@ uint32_t fdt_get_phandle(const void *fdt, int nodeoffset) const uint32_t *php; int len; - php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len); - if (!php || (len != sizeof(*php))) - return 0; + /* FIXME: This is a bit sub-optimal, since we potentially scan + * over all the properties twice. */ + php = fdt_getprop(fdt, nodeoffset, "phandle", &len); + if (!php || (len != sizeof(*php))) { + php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len); + if (!php || (len != sizeof(*php))) + return 0; + } return fdt32_to_cpu(*php); } @@ -440,11 +445,27 @@ int fdt_node_offset_by_prop_value(const void *fdt, int startoffset, int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle) { + int offset; + if ((phandle == 0) || (phandle == -1)) return -FDT_ERR_BADPHANDLE; - phandle = cpu_to_fdt32(phandle); - return fdt_node_offset_by_prop_value(fdt, -1, "linux,phandle", - &phandle, sizeof(phandle)); + + FDT_CHECK_HEADER(fdt); + + /* FIXME: The algorithm here is pretty horrible: we + * potentially scan each property of a node in + * fdt_get_phandle(), then if that didn't find what + * we want, we scan over them again making our way to the next + * node. Still it's the easiest to implement approach; + * performance can come later. */ + for (offset = fdt_next_node(fdt, -1, NULL); + offset >= 0; + offset = fdt_next_node(fdt, offset, NULL)) { + if (fdt_get_phandle(fdt, offset) == phandle) + return offset; + } + + return offset; /* error from fdt_next_node() */ } static int _fdt_stringlist_contains(const char *strlist, int listlen, |