From 4e76ec796c90d44d417f82d9db2d67cfe575f8ed Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Fri, 26 Apr 2013 05:43:31 -0700 Subject: libfdt: Add fdt_next_subnode() to permit easy subnode iteration Iterating through subnodes with libfdt is a little painful to write as we need something like this: for (depth = 0, count = 0, offset = fdt_next_node(fdt, parent_offset, &depth); (offset >= 0) && (depth > 0); offset = fdt_next_node(fdt, offset, &depth)) { if (depth == 1) { /* code body */ } } Using fdt_next_subnode() we can instead write this, which is shorter and easier to get right: for (offset = fdt_first_subnode(fdt, parent_offset); offset >= 0; offset = fdt_next_subnode(fdt, offset)) { /* code body */ } Also, it doesn't require two levels of indentation for the loop body. Signed-off-by: Simon Glass Acked-by: David Gibson --- libfdt/fdt.c | 28 ++++++++++++++ libfdt/libfdt.h | 22 +++++++++++ tests/Makefile.tests | 3 +- tests/run_tests.sh | 3 ++ tests/subnode_iterate.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++ tests/subnode_iterate.dts | 44 ++++++++++++++++++++++ 6 files changed, 193 insertions(+), 1 deletion(-) create mode 100644 tests/subnode_iterate.c create mode 100644 tests/subnode_iterate.dts diff --git a/libfdt/fdt.c b/libfdt/fdt.c index 57faba3..2ce6a44 100644 --- a/libfdt/fdt.c +++ b/libfdt/fdt.c @@ -198,6 +198,34 @@ int fdt_next_node(const void *fdt, int offset, int *depth) return offset; } +int fdt_first_subnode(const void *fdt, int offset) +{ + int depth = 0; + + offset = fdt_next_node(fdt, offset, &depth); + if (offset < 0 || depth != 1) + return -FDT_ERR_NOTFOUND; + + return offset; +} + +int fdt_next_subnode(const void *fdt, int offset) +{ + int depth = 1; + + /* + * With respect to the parent, the depth of the next subnode will be + * the same as the last. + */ + do { + offset = fdt_next_node(fdt, offset, &depth); + if (offset < 0 || depth < 1) + return -FDT_ERR_NOTFOUND; + } while (depth > 1); + + return offset; +} + const char *_fdt_find_string(const char *strtab, int tabsize, const char *s) { int len = strlen(s) + 1; diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h index 130789a..02baa84 100644 --- a/libfdt/libfdt.h +++ b/libfdt/libfdt.h @@ -136,6 +136,28 @@ uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset); int fdt_next_node(const void *fdt, int offset, int *depth); +/** + * fdt_first_subnode() - get offset of first direct subnode + * + * @fdt: FDT blob + * @offset: Offset of node to check + * @return offset of first subnode, or -FDT_ERR_NOTFOUND if there is none + */ +int fdt_first_subnode(const void *fdt, int offset); + +/** + * fdt_next_subnode() - get offset of next direct subnode + * + * After first calling fdt_first_subnode(), call this function repeatedly to + * get direct subnodes of a parent node. + * + * @fdt: FDT blob + * @offset: Offset of previous subnode + * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more + * subnodes + */ +int fdt_next_subnode(const void *fdt, int offset); + /**********************************************************************/ /* General functions */ /**********************************************************************/ diff --git a/tests/Makefile.tests b/tests/Makefile.tests index d59bff8..dafb618 100644 --- a/tests/Makefile.tests +++ b/tests/Makefile.tests @@ -20,7 +20,8 @@ LIB_TESTS_L = get_mem_rsv \ dtb_reverse dtbs_equal_unordered \ add_subnode_with_nops path_offset_aliases \ utilfdt_test \ - integer-expressions + integer-expressions \ + subnode_iterate LIB_TESTS = $(LIB_TESTS_L:%=$(TESTS_PREFIX)%) LIBTREE_TESTS_L = truncated_property diff --git a/tests/run_tests.sh b/tests/run_tests.sh index b56b626..b013761 100755 --- a/tests/run_tests.sh +++ b/tests/run_tests.sh @@ -241,6 +241,9 @@ libfdt_tests () { tree1_tests_rw noppy.$basetree done + run_dtc_test -I dts -O dtb -o subnode_iterate.dtb subnode_iterate.dts + run_test subnode_iterate subnode_iterate.dtb + # Tests for behaviour on various sorts of corrupted trees run_test truncated_property diff --git a/tests/subnode_iterate.c b/tests/subnode_iterate.c new file mode 100644 index 0000000..b9f379d --- /dev/null +++ b/tests/subnode_iterate.c @@ -0,0 +1,94 @@ +/* + * libfdt - Flat Device Tree manipulation + * Tests that fdt_next_subnode() works as expected + * + * Copyright (C) 2013 Google, Inc + * + * Copyright (C) 2007 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 "tests.h" +#include "testdata.h" + +static void test_node(void *fdt, int parent_offset) +{ + fdt32_t subnodes; + const fdt32_t *prop; + int offset; + int count; + int len; + + /* This property indicates the number of subnodes to expect */ + prop = fdt_getprop(fdt, parent_offset, "subnodes", &len); + if (!prop || len != sizeof(fdt32_t)) { + FAIL("Missing/invalid subnodes property at '%s'", + fdt_get_name(fdt, parent_offset, NULL)); + } + subnodes = cpu_to_fdt32(*prop); + + count = 0; + for (offset = fdt_first_subnode(fdt, parent_offset); + offset >= 0; + offset = fdt_next_subnode(fdt, offset)) + count++; + + if (count != subnodes) { + FAIL("Node '%s': Expected %d subnodes, got %d\n", + fdt_get_name(fdt, parent_offset, NULL), subnodes, + count); + } +} + +static void check_fdt_next_subnode(void *fdt) +{ + int offset; + int count = 0; + + for (offset = fdt_first_subnode(fdt, 0); + offset >= 0; + offset = fdt_next_subnode(fdt, offset)) { + test_node(fdt, offset); + count++; + } + + if (count != 2) + FAIL("Expected %d tests, got %d\n", 2, count); +} + +int main(int argc, char *argv[]) +{ + void *fdt; + + test_init(argc, argv); + if (argc != 2) + CONFIG("Usage: %s ", argv[0]); + + fdt = load_blob(argv[1]); + if (!fdt) + FAIL("No device tree available"); + + check_fdt_next_subnode(fdt); + + PASS(); +} diff --git a/tests/subnode_iterate.dts b/tests/subnode_iterate.dts new file mode 100644 index 0000000..14a0d3a --- /dev/null +++ b/tests/subnode_iterate.dts @@ -0,0 +1,44 @@ +/dts-v1/; + +/ { + #address-cells = <1>; + #size-cells = <0>; + + test1 { + subnodes = <2>; + linux,phandle = <0x1>; + #address-cells = <1>; + #size-cells = <0>; + PowerPC,970@0 { + name = "PowerPC,970"; + device_type = "cpu"; + reg = <0x00000000>; + clock-frequency = <1600000000>; + timebase-frequency = <33333333>; + linux,boot-cpu; + i-cache-size = <65536>; + d-cache-size = <32768>; + another-sub-node { + should-be-ignored; + yet-another { + should-also-be-ignored; + }; + }; + }; + + PowerPC,970@1 { + name = "PowerPC,970"; + device_type = "cpu"; + reg = <0x00000001>; + clock-frequency = <1600000000>; + timebase-frequency = <33333333>; + i-cache-size = <65536>; + d-cache-size = <32768>; + }; + }; + + test2 { + subnodes = <0>; + }; +}; + -- cgit v1.2.1