From 9c83115351443a132c5c1cbad6cda79d52f63489 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 20 Aug 2008 16:55:14 +1000 Subject: [PATCH] libfdt: Add function to explicitly expand aliases Kumar has already added alias expansion to fdt_path_offset(). However, in some circumstances it may be convenient for the user of libfdt to explicitly get the string expansion of an alias. This patch adds a function to do this, fdt_get_alias(), and uses it to implement fdt_path_offset(). Signed-off-by: David Gibson --- libfdt/fdt_ro.c | 26 ++++++++++++++------ libfdt/libfdt.h | 26 ++++++++++++++++++++ tests/Makefile.tests | 1 + tests/get_alias.c | 58 ++++++++++++++++++++++++++++++++++++++++++++ tests/run_tests.sh | 1 + 5 files changed, 105 insertions(+), 7 deletions(-) create mode 100644 tests/get_alias.c diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c index 1d1e35e..6365c26 100644 --- a/libfdt/fdt_ro.c +++ b/libfdt/fdt_ro.c @@ -141,17 +141,12 @@ int fdt_path_offset(const void *fdt, const char *path) /* see if we have an alias */ if (*path != '/') { - const char *q; - int aliasoffset = fdt_path_offset(fdt, "/aliases"); - - if (aliasoffset < 0) - return -FDT_ERR_BADPATH; + const char *q = strchr(path, '/'); - q = strchr(path, '/'); if (!q) q = end; - p = fdt_getprop_namelen(fdt, aliasoffset, path, q - p, NULL); + p = fdt_get_alias_namelen(fdt, p, q - p); if (!p) return -FDT_ERR_BADPATH; offset = fdt_path_offset(fdt, p); @@ -302,6 +297,23 @@ uint32_t fdt_get_phandle(const void *fdt, int nodeoffset) return fdt32_to_cpu(*php); } +const char *fdt_get_alias_namelen(const void *fdt, + const char *name, int namelen) +{ + int aliasoffset; + + aliasoffset = fdt_path_offset(fdt, "/aliases"); + if (aliasoffset < 0) + return NULL; + + return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL); +} + +const char *fdt_get_alias(const void *fdt, const char *name) +{ + return fdt_get_alias_namelen(fdt, name, strlen(name)); +} + int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen) { int pdepth = 0, p = 0; diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h index 60dd4a1..a11bbf3 100644 --- a/libfdt/libfdt.h +++ b/libfdt/libfdt.h @@ -458,6 +458,32 @@ static inline void *fdt_getprop_w(void *fdt, int nodeoffset, */ uint32_t fdt_get_phandle(const void *fdt, int nodeoffset); +/** + * fdt_get_namelen - get alias based on substring + * @fdt: pointer to the device tree blob + * @name: name of the alias th look up + * @namelen: number of characters of name to consider + * + * Identical to fdt_get_alias(), but only examine the first namelen + * characters of name for matching the alias name. + */ +const char *fdt_get_alias_namelen(const void *fdt, + const char *name, int namelen); + +/** + * fdt_get_alias - retreive the path referenced by a given alias + * @fdt: pointer to the device tree blob + * @name: name of the alias th look up + * + * fdt_get_alias() retrieves the value of a given alias. That is, the + * value of the property named 'name' in the node /aliases. + * + * returns: + * a pointer to the expansion of the alias named 'name', of it exists + * NULL, if the given alias or the /aliases node does not exist + */ +const char *fdt_get_alias(const void *fdt, const char *name); + /** * fdt_get_path - determine the full path of a node * @fdt: pointer to the device tree blob diff --git a/tests/Makefile.tests b/tests/Makefile.tests index 44021b0..5fd4d28 100644 --- a/tests/Makefile.tests +++ b/tests/Makefile.tests @@ -4,6 +4,7 @@ LIB_TESTS_L = get_mem_rsv \ get_path supernode_atdepth_offset parent_offset \ node_offset_by_prop_value node_offset_by_phandle \ node_check_compatible node_offset_by_compatible \ + get_alias \ notfound \ setprop_inplace nop_property nop_node \ sw_tree1 \ diff --git a/tests/get_alias.c b/tests/get_alias.c new file mode 100644 index 0000000..8eeaee4 --- /dev/null +++ b/tests/get_alias.c @@ -0,0 +1,58 @@ +/* + * libfdt - Flat Device Tree manipulation + * Testcase for fdt_get_alias() + * Copyright (C) 2006 David Gibson, IBM Corporation. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public License + * as published by the Free Software Foundation; either version 2.1 of + * the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include +#include +#include +#include + +#include +#include + +#include "tests.h" +#include "testdata.h" + +void check_alias(void *fdt, const char *path, const char *alias) +{ + const char *aliaspath; + + aliaspath = fdt_get_alias(fdt, alias); + + if (path && !aliaspath) + FAIL("fdt_get_alias(%s) failed\n", alias); + + if (strcmp(aliaspath, path) != 0) + FAIL("fdt_get_alias(%s) returned %s instead of %s\n", + alias, aliaspath, path); +} + +int main(int argc, char *argv[]) +{ + void *fdt; + + test_init(argc, argv); + fdt = load_blob_arg(argc, argv); + + check_alias(fdt, "/subnode@1", "s1"); + check_alias(fdt, "/subnode@1/subsubnode", "ss1"); + check_alias(fdt, "/subnode@1/subsubnode/subsubsubnode", "sss1"); + + PASS(); +} diff --git a/tests/run_tests.sh b/tests/run_tests.sh index eb29462..b424664 100755 --- a/tests/run_tests.sh +++ b/tests/run_tests.sh @@ -216,6 +216,7 @@ dtc_tests () { # Check aliases support in fdt_path_offset run_dtc_test -I dts -O dtb -o aliases.dtb aliases.dts + run_test get_alias aliases.dtb run_test path_offset_aliases aliases.dtb # Check /include/ directive