From 53acf491e9d576519f97b62984762498f9453cb4 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 7 Nov 2007 11:54:14 +1100 Subject: [PATCH] libfdt: Add more documentation (path the fifth) This patch documents a few more functions in libfdt.h. All the read-only functions are now documented. Signed-off-by: David Gibson --- libfdt/libfdt.h | 95 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h index 8a664bb..220431a 100644 --- a/libfdt/libfdt.h +++ b/libfdt/libfdt.h @@ -515,12 +515,107 @@ int fdt_node_depth(const void *fdt, int nodeoffset); */ int fdt_parent_offset(const void *fdt, int nodeoffset); +/** + * fdt_node_offset_by_prop_value - find nodes with a given property value + * @fdt: pointer to the device tree blob + * @startoffset: only find nodes after this offset + * @propname: property name to check + * @propval: property value to search for + * @proplen: length of the value in propval + * + * fdt_node_offset_by_prop_value() returns the offset of the first + * node after startoffset, which has a property named propname whose + * value is of length proplen and has value equal to propval; or if + * startoffset is -1, the very first such node in the tree. + * + * To iterate through all nodes matching the criterion, the following + * idiom can be used: + * offset = fdt_node_offset_by_prop_value(fdt, -1, propname, + * propval, proplen); + * while (offset != -FDT_ERR_NOTFOUND) { + * // other code here + * offset = fdt_node_offset_by_prop_value(fdt, offset, propname, + * propval, proplen); + * } + * + * Note the -1 in the first call to the function, if 0 is used here + * instead, the function will never locate the root node, even if it + * matches the criterion. + * + * returns: + * structure block offset of the located node (>= 0, >startoffset), + * on success + * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the + * tree after startoffset + * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, standard meanings + */ int fdt_node_offset_by_prop_value(const void *fdt, int startoffset, const char *propname, const void *propval, int proplen); +/** + * fdt_node_check_compatible: check a node's compatible property + * @fdt: pointer to the device tree blob + * @nodeoffset: offset of a tree node + * @compatible: string to match against + * + * + * fdt_node_check_compatible() returns 0 if the given node contains a + * 'compatible' property with the given string as one of its elements, + * it returns non-zero otherwise, or on error. + * + * returns: + * 0, if the node has a 'compatible' property listing the given string + * 1, if the node has a 'compatible' property, but it does not list + * the given string + * -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property + * -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, standard meanings + */ int fdt_node_check_compatible(const void *fdt, int nodeoffset, const char *compatible); + +/** + * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value + * @fdt: pointer to the device tree blob + * @startoffset: only find nodes after this offset + * @compatible: 'compatible' string to match against + * + * fdt_node_offset_by_compatible() returns the offset of the first + * node after startoffset, which has a 'compatible' property which + * lists the given compatible string; or if startoffset is -1, the + * very first such node in the tree. + * + * To iterate through all nodes matching the criterion, the following + * idiom can be used: + * offset = fdt_node_offset_by_compatible(fdt, -1, compatible); + * while (offset != -FDT_ERR_NOTFOUND) { + * // other code here + * offset = fdt_node_offset_by_compatible(fdt, offset, compatible); + * } + * + * Note the -1 in the first call to the function, if 0 is used here + * instead, the function will never locate the root node, even if it + * matches the criterion. + * + * returns: + * structure block offset of the located node (>= 0, >startoffset), + * on success + * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the + * tree after startoffset + * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag + * -FDT_ERR_BADMAGIC, + * -FDT_ERR_BADVERSION, + * -FDT_ERR_BADSTATE, + * -FDT_ERR_BADSTRUCTURE, standard meanings + */ int fdt_node_offset_by_compatible(const void *fdt, int startoffset, const char *compatible);